Remove mongo support

Resolves #40 

42 files changed, 0 insertions, 17086 deletions

diff --git a/vendor/gopkg.in/mgo.v2/LICENSE b/vendor/gopkg.in/mgo.v2/LICENSE
deleted file mode 100644
index 770c767..0000000
--- a/vendor/gopkg.in/mgo.v2/LICENSE
+++ /dev/null
@@ -1,25 +0,0 @@
-mgo - MongoDB driver for Go
-
-Copyright (c) 2010-2013 - Gustavo Niemeyer <gustavo@niemeyer.net>
-
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met: 
-
-1. Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer. 
-2. Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution. 
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/gopkg.in/mgo.v2/Makefile b/vendor/gopkg.in/mgo.v2/Makefile
deleted file mode 100644
index d1027d4..0000000
--- a/vendor/gopkg.in/mgo.v2/Makefile
+++ /dev/null
@@ -1,5 +0,0 @@
-startdb:
-	@harness/setup.sh start
-
-stopdb:
-	@harness/setup.sh stop
diff --git a/vendor/gopkg.in/mgo.v2/README.md b/vendor/gopkg.in/mgo.v2/README.md
deleted file mode 100644
index f4e452c..0000000
--- a/vendor/gopkg.in/mgo.v2/README.md
+++ /dev/null
@@ -1,4 +0,0 @@
-The MongoDB driver for Go
--------------------------
-
-Please go to [http://labix.org/mgo](http://labix.org/mgo) for all project details.
diff --git a/vendor/gopkg.in/mgo.v2/auth.go b/vendor/gopkg.in/mgo.v2/auth.go
deleted file mode 100644
index dc26e52..0000000
--- a/vendor/gopkg.in/mgo.v2/auth.go
+++ /dev/null
@@ -1,467 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"crypto/md5"
-	"crypto/sha1"
-	"encoding/hex"
-	"errors"
-	"fmt"
-	"sync"
-
-	"gopkg.in/mgo.v2/bson"
-	"gopkg.in/mgo.v2/internal/scram"
-)
-
-type authCmd struct {
-	Authenticate int
-
-	Nonce string
-	User  string
-	Key   string
-}
-
-type startSaslCmd struct {
-	StartSASL int `bson:"startSasl"`
-}
-
-type authResult struct {
-	ErrMsg string
-	Ok     bool
-}
-
-type getNonceCmd struct {
-	GetNonce int
-}
-
-type getNonceResult struct {
-	Nonce string
-	Err   string "$err"
-	Code  int
-}
-
-type logoutCmd struct {
-	Logout int
-}
-
-type saslCmd struct {
-	Start          int    `bson:"saslStart,omitempty"`
-	Continue       int    `bson:"saslContinue,omitempty"`
-	ConversationId int    `bson:"conversationId,omitempty"`
-	Mechanism      string `bson:"mechanism,omitempty"`
-	Payload        []byte
-}
-
-type saslResult struct {
-	Ok    bool `bson:"ok"`
-	NotOk bool `bson:"code"` // Server <= 2.3.2 returns ok=1 & code>0 on errors (WTF?)
-	Done  bool
-
-	ConversationId int `bson:"conversationId"`
-	Payload        []byte
-	ErrMsg         string
-}
-
-type saslStepper interface {
-	Step(serverData []byte) (clientData []byte, done bool, err error)
-	Close()
-}
-
-func (socket *mongoSocket) getNonce() (nonce string, err error) {
-	socket.Lock()
-	for socket.cachedNonce == "" && socket.dead == nil {
-		debugf("Socket %p to %s: waiting for nonce", socket, socket.addr)
-		socket.gotNonce.Wait()
-	}
-	if socket.cachedNonce == "mongos" {
-		socket.Unlock()
-		return "", errors.New("Can't authenticate with mongos; see http://j.mp/mongos-auth")
-	}
-	debugf("Socket %p to %s: got nonce", socket, socket.addr)
-	nonce, err = socket.cachedNonce, socket.dead
-	socket.cachedNonce = ""
-	socket.Unlock()
-	if err != nil {
-		nonce = ""
-	}
-	return
-}
-
-func (socket *mongoSocket) resetNonce() {
-	debugf("Socket %p to %s: requesting a new nonce", socket, socket.addr)
-	op := &queryOp{}
-	op.query = &getNonceCmd{GetNonce: 1}
-	op.collection = "admin.$cmd"
-	op.limit = -1
-	op.replyFunc = func(err error, reply *replyOp, docNum int, docData []byte) {
-		if err != nil {
-			socket.kill(errors.New("getNonce: "+err.Error()), true)
-			return
-		}
-		result := &getNonceResult{}
-		err = bson.Unmarshal(docData, &result)
-		if err != nil {
-			socket.kill(errors.New("Failed to unmarshal nonce: "+err.Error()), true)
-			return
-		}
-		debugf("Socket %p to %s: nonce unmarshalled: %#v", socket, socket.addr, result)
-		if result.Code == 13390 {
-			// mongos doesn't yet support auth (see http://j.mp/mongos-auth)
-			result.Nonce = "mongos"
-		} else if result.Nonce == "" {
-			var msg string
-			if result.Err != "" {
-				msg = fmt.Sprintf("Got an empty nonce: %s (%d)", result.Err, result.Code)
-			} else {
-				msg = "Got an empty nonce"
-			}
-			socket.kill(errors.New(msg), true)
-			return
-		}
-		socket.Lock()
-		if socket.cachedNonce != "" {
-			socket.Unlock()
-			panic("resetNonce: nonce already cached")
-		}
-		socket.cachedNonce = result.Nonce
-		socket.gotNonce.Signal()
-		socket.Unlock()
-	}
-	err := socket.Query(op)
-	if err != nil {
-		socket.kill(errors.New("resetNonce: "+err.Error()), true)
-	}
-}
-
-func (socket *mongoSocket) Login(cred Credential) error {
-	socket.Lock()
-	if cred.Mechanism == "" && socket.serverInfo.MaxWireVersion >= 3 {
-		cred.Mechanism = "SCRAM-SHA-1"
-	}
-	for _, sockCred := range socket.creds {
-		if sockCred == cred {
-			debugf("Socket %p to %s: login: db=%q user=%q (already logged in)", socket, socket.addr, cred.Source, cred.Username)
-			socket.Unlock()
-			return nil
-		}
-	}
-	if socket.dropLogout(cred) {
-		debugf("Socket %p to %s: login: db=%q user=%q (cached)", socket, socket.addr, cred.Source, cred.Username)
-		socket.creds = append(socket.creds, cred)
-		socket.Unlock()
-		return nil
-	}
-	socket.Unlock()
-
-	debugf("Socket %p to %s: login: db=%q user=%q", socket, socket.addr, cred.Source, cred.Username)
-
-	var err error
-	switch cred.Mechanism {
-	case "", "MONGODB-CR", "MONGO-CR": // Name changed to MONGODB-CR in SERVER-8501.
-		err = socket.loginClassic(cred)
-	case "PLAIN":
-		err = socket.loginPlain(cred)
-	case "MONGODB-X509":
-		err = socket.loginX509(cred)
-	default:
-		// Try SASL for everything else, if it is available.
-		err = socket.loginSASL(cred)
-	}
-
-	if err != nil {
-		debugf("Socket %p to %s: login error: %s", socket, socket.addr, err)
-	} else {
-		debugf("Socket %p to %s: login successful", socket, socket.addr)
-	}
-	return err
-}
-
-func (socket *mongoSocket) loginClassic(cred Credential) error {
-	// Note that this only works properly because this function is
-	// synchronous, which means the nonce won't get reset while we're
-	// using it and any other login requests will block waiting for a
-	// new nonce provided in the defer call below.
-	nonce, err := socket.getNonce()
-	if err != nil {
-		return err
-	}
-	defer socket.resetNonce()
-
-	psum := md5.New()
-	psum.Write([]byte(cred.Username + ":mongo:" + cred.Password))
-
-	ksum := md5.New()
-	ksum.Write([]byte(nonce + cred.Username))
-	ksum.Write([]byte(hex.EncodeToString(psum.Sum(nil))))
-
-	key := hex.EncodeToString(ksum.Sum(nil))
-
-	cmd := authCmd{Authenticate: 1, User: cred.Username, Nonce: nonce, Key: key}
-	res := authResult{}
-	return socket.loginRun(cred.Source, &cmd, &res, func() error {
-		if !res.Ok {
-			return errors.New(res.ErrMsg)
-		}
-		socket.Lock()
-		socket.dropAuth(cred.Source)
-		socket.creds = append(socket.creds, cred)
-		socket.Unlock()
-		return nil
-	})
-}
-
-type authX509Cmd struct {
-	Authenticate int
-	User         string
-	Mechanism    string
-}
-
-func (socket *mongoSocket) loginX509(cred Credential) error {
-	cmd := authX509Cmd{Authenticate: 1, User: cred.Username, Mechanism: "MONGODB-X509"}
-	res := authResult{}
-	return socket.loginRun(cred.Source, &cmd, &res, func() error {
-		if !res.Ok {
-			return errors.New(res.ErrMsg)
-		}
-		socket.Lock()
-		socket.dropAuth(cred.Source)
-		socket.creds = append(socket.creds, cred)
-		socket.Unlock()
-		return nil
-	})
-}
-
-func (socket *mongoSocket) loginPlain(cred Credential) error {
-	cmd := saslCmd{Start: 1, Mechanism: "PLAIN", Payload: []byte("\x00" + cred.Username + "\x00" + cred.Password)}
-	res := authResult{}
-	return socket.loginRun(cred.Source, &cmd, &res, func() error {
-		if !res.Ok {
-			return errors.New(res.ErrMsg)
-		}
-		socket.Lock()
-		socket.dropAuth(cred.Source)
-		socket.creds = append(socket.creds, cred)
-		socket.Unlock()
-		return nil
-	})
-}
-
-func (socket *mongoSocket) loginSASL(cred Credential) error {
-	var sasl saslStepper
-	var err error
-	if cred.Mechanism == "SCRAM-SHA-1" {
-		// SCRAM is handled without external libraries.
-		sasl = saslNewScram(cred)
-	} else if len(cred.ServiceHost) > 0 {
-		sasl, err = saslNew(cred, cred.ServiceHost)
-	} else {
-		sasl, err = saslNew(cred, socket.Server().Addr)
-	}
-	if err != nil {
-		return err
-	}
-	defer sasl.Close()
-
-	// The goal of this logic is to carry a locked socket until the
-	// local SASL step confirms the auth is valid; the socket needs to be
-	// locked so that concurrent action doesn't leave the socket in an
-	// auth state that doesn't reflect the operations that took place.
-	// As a simple case, imagine inverting login=>logout to logout=>login.
-	//
-	// The logic below works because the lock func isn't called concurrently.
-	locked := false
-	lock := func(b bool) {
-		if locked != b {
-			locked = b
-			if b {
-				socket.Lock()
-			} else {
-				socket.Unlock()
-			}
-		}
-	}
-
-	lock(true)
-	defer lock(false)
-
-	start := 1
-	cmd := saslCmd{}
-	res := saslResult{}
-	for {
-		payload, done, err := sasl.Step(res.Payload)
-		if err != nil {
-			return err
-		}
-		if done && res.Done {
-			socket.dropAuth(cred.Source)
-			socket.creds = append(socket.creds, cred)
-			break
-		}
-		lock(false)
-
-		cmd = saslCmd{
-			Start:          start,
-			Continue:       1 - start,
-			ConversationId: res.ConversationId,
-			Mechanism:      cred.Mechanism,
-			Payload:        payload,
-		}
-		start = 0
-		err = socket.loginRun(cred.Source, &cmd, &res, func() error {
-			// See the comment on lock for why this is necessary.
-			lock(true)
-			if !res.Ok || res.NotOk {
-				return fmt.Errorf("server returned error on SASL authentication step: %s", res.ErrMsg)
-			}
-			return nil
-		})
-		if err != nil {
-			return err
-		}
-		if done && res.Done {
-			socket.dropAuth(cred.Source)
-			socket.creds = append(socket.creds, cred)
-			break
-		}
-	}
-
-	return nil
-}
-
-func saslNewScram(cred Credential) *saslScram {
-	credsum := md5.New()
-	credsum.Write([]byte(cred.Username + ":mongo:" + cred.Password))
-	client := scram.NewClient(sha1.New, cred.Username, hex.EncodeToString(credsum.Sum(nil)))
-	return &saslScram{cred: cred, client: client}
-}
-
-type saslScram struct {
-	cred   Credential
-	client *scram.Client
-}
-
-func (s *saslScram) Close() {}
-
-func (s *saslScram) Step(serverData []byte) (clientData []byte, done bool, err error) {
-	more := s.client.Step(serverData)
-	return s.client.Out(), !more, s.client.Err()
-}
-
-func (socket *mongoSocket) loginRun(db string, query, result interface{}, f func() error) error {
-	var mutex sync.Mutex
-	var replyErr error
-	mutex.Lock()
-
-	op := queryOp{}
-	op.query = query
-	op.collection = db + ".$cmd"
-	op.limit = -1
-	op.replyFunc = func(err error, reply *replyOp, docNum int, docData []byte) {
-		defer mutex.Unlock()
-
-		if err != nil {
-			replyErr = err
-			return
-		}
-
-		err = bson.Unmarshal(docData, result)
-		if err != nil {
-			replyErr = err
-		} else {
-			// Must handle this within the read loop for the socket, so
-			// that concurrent login requests are properly ordered.
-			replyErr = f()
-		}
-	}
-
-	err := socket.Query(&op)
-	if err != nil {
-		return err
-	}
-	mutex.Lock() // Wait.
-	return replyErr
-}
-
-func (socket *mongoSocket) Logout(db string) {
-	socket.Lock()
-	cred, found := socket.dropAuth(db)
-	if found {
-		debugf("Socket %p to %s: logout: db=%q (flagged)", socket, socket.addr, db)
-		socket.logout = append(socket.logout, cred)
-	}
-	socket.Unlock()
-}
-
-func (socket *mongoSocket) LogoutAll() {
-	socket.Lock()
-	if l := len(socket.creds); l > 0 {
-		debugf("Socket %p to %s: logout all (flagged %d)", socket, socket.addr, l)
-		socket.logout = append(socket.logout, socket.creds...)
-		socket.creds = socket.creds[0:0]
-	}
-	socket.Unlock()
-}
-
-func (socket *mongoSocket) flushLogout() (ops []interface{}) {
-	socket.Lock()
-	if l := len(socket.logout); l > 0 {
-		debugf("Socket %p to %s: logout all (flushing %d)", socket, socket.addr, l)
-		for i := 0; i != l; i++ {
-			op := queryOp{}
-			op.query = &logoutCmd{1}
-			op.collection = socket.logout[i].Source + ".$cmd"
-			op.limit = -1
-			ops = append(ops, &op)
-		}
-		socket.logout = socket.logout[0:0]
-	}
-	socket.Unlock()
-	return
-}
-
-func (socket *mongoSocket) dropAuth(db string) (cred Credential, found bool) {
-	for i, sockCred := range socket.creds {
-		if sockCred.Source == db {
-			copy(socket.creds[i:], socket.creds[i+1:])
-			socket.creds = socket.creds[:len(socket.creds)-1]
-			return sockCred, true
-		}
-	}
-	return cred, false
-}
-
-func (socket *mongoSocket) dropLogout(cred Credential) (found bool) {
-	for i, sockCred := range socket.logout {
-		if sockCred == cred {
-			copy(socket.logout[i:], socket.logout[i+1:])
-			socket.logout = socket.logout[:len(socket.logout)-1]
-			return true
-		}
-	}
-	return false
-}
diff --git a/vendor/gopkg.in/mgo.v2/bson/LICENSE b/vendor/gopkg.in/mgo.v2/bson/LICENSE
deleted file mode 100644
index 8903260..0000000
--- a/vendor/gopkg.in/mgo.v2/bson/LICENSE
+++ /dev/null
@@ -1,25 +0,0 @@
-BSON library for Go
-
-Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met: 
-
-1. Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer. 
-2. Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution. 
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/gopkg.in/mgo.v2/bson/bson.go b/vendor/gopkg.in/mgo.v2/bson/bson.go
deleted file mode 100644
index 7fb7f8c..0000000
--- a/vendor/gopkg.in/mgo.v2/bson/bson.go
+++ /dev/null
@@ -1,738 +0,0 @@
-// BSON library for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// Package bson is an implementation of the BSON specification for Go:
-//
-//     http://bsonspec.org
-//
-// It was created as part of the mgo MongoDB driver for Go, but is standalone
-// and may be used on its own without the driver.
-package bson
-
-import (
-	"bytes"
-	"crypto/md5"
-	"crypto/rand"
-	"encoding/binary"
-	"encoding/hex"
-	"encoding/json"
-	"errors"
-	"fmt"
-	"io"
-	"os"
-	"reflect"
-	"runtime"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"time"
-)
-
-// --------------------------------------------------------------------------
-// The public API.
-
-// A value implementing the bson.Getter interface will have its GetBSON
-// method called when the given value has to be marshalled, and the result
-// of this method will be marshaled in place of the actual object.
-//
-// If GetBSON returns return a non-nil error, the marshalling procedure
-// will stop and error out with the provided value.
-type Getter interface {
-	GetBSON() (interface{}, error)
-}
-
-// A value implementing the bson.Setter interface will receive the BSON
-// value via the SetBSON method during unmarshaling, and the object
-// itself will not be changed as usual.
-//
-// If setting the value works, the method should return nil or alternatively
-// bson.SetZero to set the respective field to its zero value (nil for
-// pointer types). If SetBSON returns a value of type bson.TypeError, the
-// BSON value will be omitted from a map or slice being decoded and the
-// unmarshalling will continue. If it returns any other non-nil error, the
-// unmarshalling procedure will stop and error out with the provided value.
-//
-// This interface is generally useful in pointer receivers, since the method
-// will want to change the receiver. A type field that implements the Setter
-// interface doesn't have to be a pointer, though.
-//
-// Unlike the usual behavior, unmarshalling onto a value that implements a
-// Setter interface will NOT reset the value to its zero state. This allows
-// the value to decide by itself how to be unmarshalled.
-//
-// For example:
-//
-//     type MyString string
-//
-//     func (s *MyString) SetBSON(raw bson.Raw) error {
-//         return raw.Unmarshal(s)
-//     }
-//
-type Setter interface {
-	SetBSON(raw Raw) error
-}
-
-// SetZero may be returned from a SetBSON method to have the value set to
-// its respective zero value. When used in pointer values, this will set the
-// field to nil rather than to the pre-allocated value.
-var SetZero = errors.New("set to zero")
-
-// M is a convenient alias for a map[string]interface{} map, useful for
-// dealing with BSON in a native way.  For instance:
-//
-//     bson.M{"a": 1, "b": true}
-//
-// There's no special handling for this type in addition to what's done anyway
-// for an equivalent map type.  Elements in the map will be dumped in an
-// undefined ordered. See also the bson.D type for an ordered alternative.
-type M map[string]interface{}
-
-// D represents a BSON document containing ordered elements. For example:
-//
-//     bson.D{{"a", 1}, {"b", true}}
-//
-// In some situations, such as when creating indexes for MongoDB, the order in
-// which the elements are defined is important.  If the order is not important,
-// using a map is generally more comfortable. See bson.M and bson.RawD.
-type D []DocElem
-
-// DocElem is an element of the bson.D document representation.
-type DocElem struct {
-	Name  string
-	Value interface{}
-}
-
-// Map returns a map out of the ordered element name/value pairs in d.
-func (d D) Map() (m M) {
-	m = make(M, len(d))
-	for _, item := range d {
-		m[item.Name] = item.Value
-	}
-	return m
-}
-
-// The Raw type represents raw unprocessed BSON documents and elements.
-// Kind is the kind of element as defined per the BSON specification, and
-// Data is the raw unprocessed data for the respective element.
-// Using this type it is possible to unmarshal or marshal values partially.
-//
-// Relevant documentation:
-//
-//     http://bsonspec.org/#/specification
-//
-type Raw struct {
-	Kind byte
-	Data []byte
-}
-
-// RawD represents a BSON document containing raw unprocessed elements.
-// This low-level representation may be useful when lazily processing
-// documents of uncertain content, or when manipulating the raw content
-// documents in general.
-type RawD []RawDocElem
-
-// See the RawD type.
-type RawDocElem struct {
-	Name  string
-	Value Raw
-}
-
-// ObjectId is a unique ID identifying a BSON value. It must be exactly 12 bytes
-// long. MongoDB objects by default have such a property set in their "_id"
-// property.
-//
-// http://www.mongodb.org/display/DOCS/Object+IDs
-type ObjectId string
-
-// ObjectIdHex returns an ObjectId from the provided hex representation.
-// Calling this function with an invalid hex representation will
-// cause a runtime panic. See the IsObjectIdHex function.
-func ObjectIdHex(s string) ObjectId {
-	d, err := hex.DecodeString(s)
-	if err != nil || len(d) != 12 {
-		panic(fmt.Sprintf("invalid input to ObjectIdHex: %q", s))
-	}
-	return ObjectId(d)
-}
-
-// IsObjectIdHex returns whether s is a valid hex representation of
-// an ObjectId. See the ObjectIdHex function.
-func IsObjectIdHex(s string) bool {
-	if len(s) != 24 {
-		return false
-	}
-	_, err := hex.DecodeString(s)
-	return err == nil
-}
-
-// objectIdCounter is atomically incremented when generating a new ObjectId
-// using NewObjectId() function. It's used as a counter part of an id.
-var objectIdCounter uint32 = readRandomUint32()
-
-// readRandomUint32 returns a random objectIdCounter.
-func readRandomUint32() uint32 {
-	var b [4]byte
-	_, err := io.ReadFull(rand.Reader, b[:])
-	if err != nil {
-		panic(fmt.Errorf("cannot read random object id: %v", err))
-	}
-	return uint32((uint32(b[0]) << 0) | (uint32(b[1]) << 8) | (uint32(b[2]) << 16) | (uint32(b[3]) << 24))
-}
-
-// machineId stores machine id generated once and used in subsequent calls
-// to NewObjectId function.
-var machineId = readMachineId()
-var processId = os.Getpid()
-
-// readMachineId generates and returns a machine id.
-// If this function fails to get the hostname it will cause a runtime error.
-func readMachineId() []byte {
-	var sum [3]byte
-	id := sum[:]
-	hostname, err1 := os.Hostname()
-	if err1 != nil {
-		_, err2 := io.ReadFull(rand.Reader, id)
-		if err2 != nil {
-			panic(fmt.Errorf("cannot get hostname: %v; %v", err1, err2))
-		}
-		return id
-	}
-	hw := md5.New()
-	hw.Write([]byte(hostname))
-	copy(id, hw.Sum(nil))
-	return id
-}
-
-// NewObjectId returns a new unique ObjectId.
-func NewObjectId() ObjectId {
-	var b [12]byte
-	// Timestamp, 4 bytes, big endian
-	binary.BigEndian.PutUint32(b[:], uint32(time.Now().Unix()))
-	// Machine, first 3 bytes of md5(hostname)
-	b[4] = machineId[0]
-	b[5] = machineId[1]
-	b[6] = machineId[2]
-	// Pid, 2 bytes, specs don't specify endianness, but we use big endian.
-	b[7] = byte(processId >> 8)
-	b[8] = byte(processId)
-	// Increment, 3 bytes, big endian
-	i := atomic.AddUint32(&objectIdCounter, 1)
-	b[9] = byte(i >> 16)
-	b[10] = byte(i >> 8)
-	b[11] = byte(i)
-	return ObjectId(b[:])
-}
-
-// NewObjectIdWithTime returns a dummy ObjectId with the timestamp part filled
-// with the provided number of seconds from epoch UTC, and all other parts
-// filled with zeroes. It's not safe to insert a document with an id generated
-// by this method, it is useful only for queries to find documents with ids
-// generated before or after the specified timestamp.
-func NewObjectIdWithTime(t time.Time) ObjectId {
-	var b [12]byte
-	binary.BigEndian.PutUint32(b[:4], uint32(t.Unix()))
-	return ObjectId(string(b[:]))
-}
-
-// String returns a hex string representation of the id.
-// Example: ObjectIdHex("4d88e15b60f486e428412dc9").
-func (id ObjectId) String() string {
-	return fmt.Sprintf(`ObjectIdHex("%x")`, string(id))
-}
-
-// Hex returns a hex representation of the ObjectId.
-func (id ObjectId) Hex() string {
-	return hex.EncodeToString([]byte(id))
-}
-
-// MarshalJSON turns a bson.ObjectId into a json.Marshaller.
-func (id ObjectId) MarshalJSON() ([]byte, error) {
-	return []byte(fmt.Sprintf(`"%x"`, string(id))), nil
-}
-
-var nullBytes = []byte("null")
-
-// UnmarshalJSON turns *bson.ObjectId into a json.Unmarshaller.
-func (id *ObjectId) UnmarshalJSON(data []byte) error {
-	if len(data) > 0 && (data[0] == '{' || data[0] == 'O') {
-		var v struct {
-			Id json.RawMessage `json:"$oid"`
-			Func struct {
-				Id json.RawMessage
-			} `json:"$oidFunc"`
-		}
-		err := jdec(data, &v)
-		if err == nil {
-			if len(v.Id) > 0 {
-				data = []byte(v.Id)
-			} else {
-				data = []byte(v.Func.Id)
-			}
-		}
-	}
-	if len(data) == 2 && data[0] == '"' && data[1] == '"' || bytes.Equal(data, nullBytes) {
-		*id = ""
-		return nil
-	}
-	if len(data) != 26 || data[0] != '"' || data[25] != '"' {
-		return errors.New(fmt.Sprintf("invalid ObjectId in JSON: %s", string(data)))
-	}
-	var buf [12]byte
-	_, err := hex.Decode(buf[:], data[1:25])
-	if err != nil {
-		return errors.New(fmt.Sprintf("invalid ObjectId in JSON: %s (%s)", string(data), err))
-	}
-	*id = ObjectId(string(buf[:]))
-	return nil
-}
-
-// MarshalText turns bson.ObjectId into an encoding.TextMarshaler.
-func (id ObjectId) MarshalText() ([]byte, error) {
-	return []byte(fmt.Sprintf("%x", string(id))), nil
-}
-
-// UnmarshalText turns *bson.ObjectId into an encoding.TextUnmarshaler.
-func (id *ObjectId) UnmarshalText(data []byte) error {
-	if len(data) == 1 && data[0] == ' ' || len(data) == 0 {
-		*id = ""
-		return nil
-	}
-	if len(data) != 24 {
-		return fmt.Errorf("invalid ObjectId: %s", data)
-	}
-	var buf [12]byte
-	_, err := hex.Decode(buf[:], data[:])
-	if err != nil {
-		return fmt.Errorf("invalid ObjectId: %s (%s)", data, err)
-	}
-	*id = ObjectId(string(buf[:]))
-	return nil
-}
-
-// Valid returns true if id is valid. A valid id must contain exactly 12 bytes.
-func (id ObjectId) Valid() bool {
-	return len(id) == 12
-}
-
-// byteSlice returns byte slice of id from start to end.
-// Calling this function with an invalid id will cause a runtime panic.
-func (id ObjectId) byteSlice(start, end int) []byte {
-	if len(id) != 12 {
-		panic(fmt.Sprintf("invalid ObjectId: %q", string(id)))
-	}
-	return []byte(string(id)[start:end])
-}
-
-// Time returns the timestamp part of the id.
-// It's a runtime error to call this method with an invalid id.
-func (id ObjectId) Time() time.Time {
-	// First 4 bytes of ObjectId is 32-bit big-endian seconds from epoch.
-	secs := int64(binary.BigEndian.Uint32(id.byteSlice(0, 4)))
-	return time.Unix(secs, 0)
-}
-
-// Machine returns the 3-byte machine id part of the id.
-// It's a runtime error to call this method with an invalid id.
-func (id ObjectId) Machine() []byte {
-	return id.byteSlice(4, 7)
-}
-
-// Pid returns the process id part of the id.
-// It's a runtime error to call this method with an invalid id.
-func (id ObjectId) Pid() uint16 {
-	return binary.BigEndian.Uint16(id.byteSlice(7, 9))
-}
-
-// Counter returns the incrementing value part of the id.
-// It's a runtime error to call this method with an invalid id.
-func (id ObjectId) Counter() int32 {
-	b := id.byteSlice(9, 12)
-	// Counter is stored as big-endian 3-byte value
-	return int32(uint32(b[0])<<16 | uint32(b[1])<<8 | uint32(b[2]))
-}
-
-// The Symbol type is similar to a string and is used in languages with a
-// distinct symbol type.
-type Symbol string
-
-// Now returns the current time with millisecond precision. MongoDB stores
-// timestamps with the same precision, so a Time returned from this method
-// will not change after a roundtrip to the database. That's the only reason
-// why this function exists. Using the time.Now function also works fine
-// otherwise.
-func Now() time.Time {
-	return time.Unix(0, time.Now().UnixNano()/1e6*1e6)
-}
-
-// MongoTimestamp is a special internal type used by MongoDB that for some
-// strange reason has its own datatype defined in BSON.
-type MongoTimestamp int64
-
-type orderKey int64
-
-// MaxKey is a special value that compares higher than all other possible BSON
-// values in a MongoDB database.
-var MaxKey = orderKey(1<<63 - 1)
-
-// MinKey is a special value that compares lower than all other possible BSON
-// values in a MongoDB database.
-var MinKey = orderKey(-1 << 63)
-
-type undefined struct{}
-
-// Undefined represents the undefined BSON value.
-var Undefined undefined
-
-// Binary is a representation for non-standard binary values.  Any kind should
-// work, but the following are known as of this writing:
-//
-//   0x00 - Generic. This is decoded as []byte(data), not Binary{0x00, data}.
-//   0x01 - Function (!?)
-//   0x02 - Obsolete generic.
-//   0x03 - UUID
-//   0x05 - MD5
-//   0x80 - User defined.
-//
-type Binary struct {
-	Kind byte
-	Data []byte
-}
-
-// RegEx represents a regular expression.  The Options field may contain
-// individual characters defining the way in which the pattern should be
-// applied, and must be sorted. Valid options as of this writing are 'i' for
-// case insensitive matching, 'm' for multi-line matching, 'x' for verbose
-// mode, 'l' to make \w, \W, and similar be locale-dependent, 's' for dot-all
-// mode (a '.' matches everything), and 'u' to make \w, \W, and similar match
-// unicode. The value of the Options parameter is not verified before being
-// marshaled into the BSON format.
-type RegEx struct {
-	Pattern string
-	Options string
-}
-
-// JavaScript is a type that holds JavaScript code. If Scope is non-nil, it
-// will be marshaled as a mapping from identifiers to values that may be
-// used when evaluating the provided Code.
-type JavaScript struct {
-	Code  string
-	Scope interface{}
-}
-
-// DBPointer refers to a document id in a namespace.
-//
-// This type is deprecated in the BSON specification and should not be used
-// except for backwards compatibility with ancient applications.
-type DBPointer struct {
-	Namespace string
-	Id        ObjectId
-}
-
-const initialBufferSize = 64
-
-func handleErr(err *error) {
-	if r := recover(); r != nil {
-		if _, ok := r.(runtime.Error); ok {
-			panic(r)
-		} else if _, ok := r.(externalPanic); ok {
-			panic(r)
-		} else if s, ok := r.(string); ok {
-			*err = errors.New(s)
-		} else if e, ok := r.(error); ok {
-			*err = e
-		} else {
-			panic(r)
-		}
-	}
-}
-
-// Marshal serializes the in value, which may be a map or a struct value.
-// In the case of struct values, only exported fields will be serialized,
-// and the order of serialized fields will match that of the struct itself.
-// The lowercased field name is used as the key for each exported field,
-// but this behavior may be changed using the respective field tag.
-// The tag may also contain flags to tweak the marshalling behavior for
-// the field. The tag formats accepted are:
-//
-//     "[<key>][,<flag1>[,<flag2>]]"
-//
-//     `(...) bson:"[<key>][,<flag1>[,<flag2>]]" (...)`
-//
-// The following flags are currently supported:
-//
-//     omitempty  Only include the field if it's not set to the zero
-//                value for the type or to empty slices or maps.
-//
-//     minsize    Marshal an int64 value as an int32, if that's feasible
-//                while preserving the numeric value.
-//
-//     inline     Inline the field, which must be a struct or a map,
-//                causing all of its fields or keys to be processed as if
-//                they were part of the outer struct. For maps, keys must
-//                not conflict with the bson keys of other struct fields.
-//
-// Some examples:
-//
-//     type T struct {
-//         A bool
-//         B int    "myb"
-//         C string "myc,omitempty"
-//         D string `bson:",omitempty" json:"jsonkey"`
-//         E int64  ",minsize"
-//         F int64  "myf,omitempty,minsize"
-//     }
-//
-func Marshal(in interface{}) (out []byte, err error) {
-	defer handleErr(&err)
-	e := &encoder{make([]byte, 0, initialBufferSize)}
-	e.addDoc(reflect.ValueOf(in))
-	return e.out, nil
-}
-
-// Unmarshal deserializes data from in into the out value.  The out value
-// must be a map, a pointer to a struct, or a pointer to a bson.D value.
-// In the case of struct values, only exported fields will be deserialized.
-// The lowercased field name is used as the key for each exported field,
-// but this behavior may be changed using the respective field tag.
-// The tag may also contain flags to tweak the marshalling behavior for
-// the field. The tag formats accepted are:
-//
-//     "[<key>][,<flag1>[,<flag2>]]"
-//
-//     `(...) bson:"[<key>][,<flag1>[,<flag2>]]" (...)`
-//
-// The following flags are currently supported during unmarshal (see the
-// Marshal method for other flags):
-//
-//     inline     Inline the field, which must be a struct or a map.
-//                Inlined structs are handled as if its fields were part
-//                of the outer struct. An inlined map causes keys that do
-//                not match any other struct field to be inserted in the
-//                map rather than being discarded as usual.
-//
-// The target field or element types of out may not necessarily match
-// the BSON values of the provided data.  The following conversions are
-// made automatically:
-//
-// - Numeric types are converted if at least the integer part of the
-//   value would be preserved correctly
-// - Bools are converted to numeric types as 1 or 0
-// - Numeric types are converted to bools as true if not 0 or false otherwise
-// - Binary and string BSON data is converted to a string, array or byte slice
-//
-// If the value would not fit the type and cannot be converted, it's
-// silently skipped.
-//
-// Pointer values are initialized when necessary.
-func Unmarshal(in []byte, out interface{}) (err error) {
-	if raw, ok := out.(*Raw); ok {
-		raw.Kind = 3
-		raw.Data = in
-		return nil
-	}
-	defer handleErr(&err)
-	v := reflect.ValueOf(out)
-	switch v.Kind() {
-	case reflect.Ptr:
-		fallthrough
-	case reflect.Map:
-		d := newDecoder(in)
-		d.readDocTo(v)
-	case reflect.Struct:
-		return errors.New("Unmarshal can't deal with struct values. Use a pointer.")
-	default:
-		return errors.New("Unmarshal needs a map or a pointer to a struct.")
-	}
-	return nil
-}
-
-// Unmarshal deserializes raw into the out value.  If the out value type
-// is not compatible with raw, a *bson.TypeError is returned.
-//
-// See the Unmarshal function documentation for more details on the
-// unmarshalling process.
-func (raw Raw) Unmarshal(out interface{}) (err error) {
-	defer handleErr(&err)
-	v := reflect.ValueOf(out)
-	switch v.Kind() {
-	case reflect.Ptr:
-		v = v.Elem()
-		fallthrough
-	case reflect.Map:
-		d := newDecoder(raw.Data)
-		good := d.readElemTo(v, raw.Kind)
-		if !good {
-			return &TypeError{v.Type(), raw.Kind}
-		}
-	case reflect.Struct:
-		return errors.New("Raw Unmarshal can't deal with struct values. Use a pointer.")
-	default:
-		return errors.New("Raw Unmarshal needs a map or a valid pointer.")
-	}
-	return nil
-}
-
-type TypeError struct {
-	Type reflect.Type
-	Kind byte
-}
-
-func (e *TypeError) Error() string {
-	return fmt.Sprintf("BSON kind 0x%02x isn't compatible with type %s", e.Kind, e.Type.String())
-}
-
-// --------------------------------------------------------------------------
-// Maintain a mapping of keys to structure field indexes
-
-type structInfo struct {
-	FieldsMap  map[string]fieldInfo
-	FieldsList []fieldInfo
-	InlineMap  int
-	Zero       reflect.Value
-}
-
-type fieldInfo struct {
-	Key       string
-	Num       int
-	OmitEmpty bool
-	MinSize   bool
-	Inline    []int
-}
-
-var structMap = make(map[reflect.Type]*structInfo)
-var structMapMutex sync.RWMutex
-
-type externalPanic string
-
-func (e externalPanic) String() string {
-	return string(e)
-}
-
-func getStructInfo(st reflect.Type) (*structInfo, error) {
-	structMapMutex.RLock()
-	sinfo, found := structMap[st]
-	structMapMutex.RUnlock()
-	if found {
-		return sinfo, nil
-	}
-	n := st.NumField()
-	fieldsMap := make(map[string]fieldInfo)
-	fieldsList := make([]fieldInfo, 0, n)
-	inlineMap := -1
-	for i := 0; i != n; i++ {
-		field := st.Field(i)
-		if field.PkgPath != "" && !field.Anonymous {
-			continue // Private field
-		}
-
-		info := fieldInfo{Num: i}
-
-		tag := field.Tag.Get("bson")
-		if tag == "" && strings.Index(string(field.Tag), ":") < 0 {
-			tag = string(field.Tag)
-		}
-		if tag == "-" {
-			continue
-		}
-
-		inline := false
-		fields := strings.Split(tag, ",")
-		if len(fields) > 1 {
-			for _, flag := range fields[1:] {
-				switch flag {
-				case "omitempty":
-					info.OmitEmpty = true
-				case "minsize":
-					info.MinSize = true
-				case "inline":
-					inline = true
-				default:
-					msg := fmt.Sprintf("Unsupported flag %q in tag %q of type %s", flag, tag, st)
-					panic(externalPanic(msg))
-				}
-			}
-			tag = fields[0]
-		}
-
-		if inline {
-			switch field.Type.Kind() {
-			case reflect.Map:
-				if inlineMap >= 0 {
-					return nil, errors.New("Multiple ,inline maps in struct " + st.String())
-				}
-				if field.Type.Key() != reflect.TypeOf("") {
-					return nil, errors.New("Option ,inline needs a map with string keys in struct " + st.String())
-				}
-				inlineMap = info.Num
-			case reflect.Struct:
-				sinfo, err := getStructInfo(field.Type)
-				if err != nil {
-					return nil, err
-				}
-				for _, finfo := range sinfo.FieldsList {
-					if _, found := fieldsMap[finfo.Key]; found {
-						msg := "Duplicated key '" + finfo.Key + "' in struct " + st.String()
-						return nil, errors.New(msg)
-					}
-					if finfo.Inline == nil {
-						finfo.Inline = []int{i, finfo.Num}
-					} else {
-						finfo.Inline = append([]int{i}, finfo.Inline...)
-					}
-					fieldsMap[finfo.Key] = finfo
-					fieldsList = append(fieldsList, finfo)
-				}
-			default:
-				panic("Option ,inline needs a struct value or map field")
-			}
-			continue
-		}
-
-		if tag != "" {
-			info.Key = tag
-		} else {
-			info.Key = strings.ToLower(field.Name)
-		}
-
-		if _, found = fieldsMap[info.Key]; found {
-			msg := "Duplicated key '" + info.Key + "' in struct " + st.String()
-			return nil, errors.New(msg)
-		}
-
-		fieldsList = append(fieldsList, info)
-		fieldsMap[info.Key] = info
-	}
-	sinfo = &structInfo{
-		fieldsMap,
-		fieldsList,
-		inlineMap,
-		reflect.New(st).Elem(),
-	}
-	structMapMutex.Lock()
-	structMap[st] = sinfo
-	structMapMutex.Unlock()
-	return sinfo, nil
-}
diff --git a/vendor/gopkg.in/mgo.v2/bson/decimal.go b/vendor/gopkg.in/mgo.v2/bson/decimal.go
deleted file mode 100644
index 3d2f700..0000000
--- a/vendor/gopkg.in/mgo.v2/bson/decimal.go
+++ /dev/null
@@ -1,310 +0,0 @@
-// BSON library for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package bson
-
-import (
-	"fmt"
-	"strconv"
-	"strings"
-)
-
-// Decimal128 holds decimal128 BSON values.
-type Decimal128 struct {
-	h, l uint64
-}
-
-func (d Decimal128) String() string {
-	var pos int     // positive sign
-	var e int       // exponent
-	var h, l uint64 // significand high/low
-
-	if d.h>>63&1 == 0 {
-		pos = 1
-	}
-
-	switch d.h >> 58 & (1<<5 - 1) {
-	case 0x1F:
-		return "NaN"
-	case 0x1E:
-		return "-Inf"[pos:]
-	}
-
-	l = d.l
-	if d.h>>61&3 == 3 {
-		// Bits: 1*sign 2*ignored 14*exponent 111*significand.
-		// Implicit 0b100 prefix in significand.
-		e = int(d.h>>47&(1<<14-1)) - 6176
-		//h = 4<<47 | d.h&(1<<47-1)
-		// Spec says all of these values are out of range.
-		h, l = 0, 0
-	} else {
-		// Bits: 1*sign 14*exponent 113*significand
-		e = int(d.h>>49&(1<<14-1)) - 6176
-		h = d.h & (1<<49 - 1)
-	}
-
-	// Would be handled by the logic below, but that's trivial and common.
-	if h == 0 && l == 0 && e == 0 {
-		return "-0"[pos:]
-	}
-
-	var repr [48]byte // Loop 5 times over 9 digits plus dot, negative sign, and leading zero.
-	var last = len(repr)
-	var i = len(repr)
-	var dot = len(repr) + e
-	var rem uint32
-Loop:
-	for d9 := 0; d9 < 5; d9++ {
-		h, l, rem = divmod(h, l, 1e9)
-		for d1 := 0; d1 < 9; d1++ {
-			// Handle "-0.0", "0.00123400", "-1.00E-6", "1.050E+3", etc.
-			if i < len(repr) && (dot == i || l == 0 && h == 0 && rem > 0 && rem < 10 && (dot < i-6 || e > 0)) {
-				e += len(repr) - i
-				i--
-				repr[i] = '.'
-				last = i - 1
-				dot = len(repr) // Unmark.
-			}
-			c := '0' + byte(rem%10)
-			rem /= 10
-			i--
-			repr[i] = c
-			// Handle "0E+3", "1E+3", etc.
-			if l == 0 && h == 0 && rem == 0 && i == len(repr)-1 && (dot < i-5 || e > 0) {
-				last = i
-				break Loop
-			}
-			if c != '0' {
-				last = i
-			}
-			// Break early. Works without it, but why.
-			if dot > i && l == 0 && h == 0 && rem == 0 {
-				break Loop
-			}
-		}
-	}
-	repr[last-1] = '-'
-	last--
-
-	if e > 0 {
-		return string(repr[last+pos:]) + "E+" + strconv.Itoa(e)
-	}
-	if e < 0 {
-		return string(repr[last+pos:]) + "E" + strconv.Itoa(e)
-	}
-	return string(repr[last+pos:])
-}
-
-func divmod(h, l uint64, div uint32) (qh, ql uint64, rem uint32) {
-	div64 := uint64(div)
-	a := h >> 32
-	aq := a / div64
-	ar := a % div64
-	b := ar<<32 + h&(1<<32-1)
-	bq := b / div64
-	br := b % div64
-	c := br<<32 + l>>32
-	cq := c / div64
-	cr := c % div64
-	d := cr<<32 + l&(1<<32-1)
-	dq := d / div64
-	dr := d % div64
-	return (aq<<32 | bq), (cq<<32 | dq), uint32(dr)
-}
-
-var dNaN = Decimal128{0x1F << 58, 0}
-var dPosInf = Decimal128{0x1E << 58, 0}
-var dNegInf = Decimal128{0x3E << 58, 0}
-
-func dErr(s string) (Decimal128, error) {
-	return dNaN, fmt.Errorf("cannot parse %q as a decimal128", s)
-}
-
-func ParseDecimal128(s string) (Decimal128, error) {
-	orig := s
-	if s == "" {
-		return dErr(orig)
-	}
-	neg := s[0] == '-'
-	if neg || s[0] == '+' {
-		s = s[1:]
-	}
-
-	if (len(s) == 3 || len(s) == 8) && (s[0] == 'N' || s[0] == 'n' || s[0] == 'I' || s[0] == 'i') {
-		if s == "NaN" || s == "nan" || strings.EqualFold(s, "nan") {
-			return dNaN, nil
-		}
-		if s == "Inf" || s == "inf" || strings.EqualFold(s, "inf") || strings.EqualFold(s, "infinity") {
-			if neg {
-				return dNegInf, nil
-			}
-			return dPosInf, nil
-		}
-		return dErr(orig)
-	}
-
-	var h, l uint64
-	var e int
-
-	var add, ovr uint32
-	var mul uint32 = 1
-	var dot = -1
-	var digits = 0
-	var i = 0
-	for i < len(s) {
-		c := s[i]
-		if mul == 1e9 {
-			h, l, ovr = muladd(h, l, mul, add)
-			mul, add = 1, 0
-			if ovr > 0 || h&((1<<15-1)<<49) > 0 {
-				return dErr(orig)
-			}
-		}
-		if c >= '0' && c <= '9' {
-			i++
-			if c > '0' || digits > 0 {
-				digits++
-			}
-			if digits > 34 {
-				if c == '0' {
-					// Exact rounding.
-					e++
-					continue
-				}
-				return dErr(orig)
-			}
-			mul *= 10
-			add *= 10
-			add += uint32(c - '0')
-			continue
-		}
-		if c == '.' {
-			i++
-			if dot >= 0 || i == 1 && len(s) == 1 {
-				return dErr(orig)
-			}
-			if i == len(s) {
-				break
-			}
-			if s[i] < '0' || s[i] > '9' || e > 0 {
-				return dErr(orig)
-			}
-			dot = i
-			continue
-		}
-		break
-	}
-	if i == 0 {
-		return dErr(orig)
-	}
-	if mul > 1 {
-		h, l, ovr = muladd(h, l, mul, add)
-		if ovr > 0 || h&((1<<15-1)<<49) > 0 {
-			return dErr(orig)
-		}
-	}
-	if dot >= 0 {
-		e += dot - i
-	}
-	if i+1 < len(s) && (s[i] == 'E' || s[i] == 'e') {
-		i++
-		eneg := s[i] == '-'
-		if eneg || s[i] == '+' {
-			i++
-			if i == len(s) {
-				return dErr(orig)
-			}
-		}
-		n := 0
-		for i < len(s) && n < 1e4 {
-			c := s[i]
-			i++
-			if c < '0' || c > '9' {
-				return dErr(orig)
-			}
-			n *= 10
-			n += int(c - '0')
-		}
-		if eneg {
-			n = -n
-		}
-		e += n
-		for e < -6176 {
-			// Subnormal.
-			var div uint32 = 1
-			for div < 1e9 && e < -6176 {
-				div *= 10
-				e++
-			}
-			var rem uint32
-			h, l, rem = divmod(h, l, div)
-			if rem > 0 {
-				return dErr(orig)
-			}
-		}
-		for e > 6111 {
-			// Clamped.
-			var mul uint32 = 1
-			for mul < 1e9 && e > 6111 {
-				mul *= 10
-				e--
-			}
-			h, l, ovr = muladd(h, l, mul, 0)
-			if ovr > 0 || h&((1<<15-1)<<49) > 0 {
-				return dErr(orig)
-			}
-		}
-		if e < -6176 || e > 6111 {
-			return dErr(orig)
-		}
-	}
-
-	if i < len(s) {
-		return dErr(orig)
-	}
-
-	h |= uint64(e+6176) & uint64(1<<14-1) << 49
-	if neg {
-		h |= 1 << 63
-	}
-	return Decimal128{h, l}, nil
-}
-
-func muladd(h, l uint64, mul uint32, add uint32) (resh, resl uint64, overflow uint32) {
-	mul64 := uint64(mul)
-	a := mul64 * (l & (1<<32 - 1))
-	b := a>>32 + mul64*(l>>32)
-	c := b>>32 + mul64*(h&(1<<32-1))
-	d := c>>32 + mul64*(h>>32)
-
-	a = a&(1<<32-1) + uint64(add)
-	b = b&(1<<32-1) + a>>32
-	c = c&(1<<32-1) + b>>32
-	d = d&(1<<32-1) + c>>32
-
-	return (d<<32 | c&(1<<32-1)), (b<<32 | a&(1<<32-1)), uint32(d >> 32)
-}
diff --git a/vendor/gopkg.in/mgo.v2/bson/decode.go b/vendor/gopkg.in/mgo.v2/bson/decode.go
deleted file mode 100644
index 7c2d841..0000000
--- a/vendor/gopkg.in/mgo.v2/bson/decode.go
+++ /dev/null
@@ -1,849 +0,0 @@
-// BSON library for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-// gobson - BSON library for Go.
-
-package bson
-
-import (
-	"fmt"
-	"math"
-	"net/url"
-	"reflect"
-	"strconv"
-	"sync"
-	"time"
-)
-
-type decoder struct {
-	in      []byte
-	i       int
-	docType reflect.Type
-}
-
-var typeM = reflect.TypeOf(M{})
-
-func newDecoder(in []byte) *decoder {
-	return &decoder{in, 0, typeM}
-}
-
-// --------------------------------------------------------------------------
-// Some helper functions.
-
-func corrupted() {
-	panic("Document is corrupted")
-}
-
-func settableValueOf(i interface{}) reflect.Value {
-	v := reflect.ValueOf(i)
-	sv := reflect.New(v.Type()).Elem()
-	sv.Set(v)
-	return sv
-}
-
-// --------------------------------------------------------------------------
-// Unmarshaling of documents.
-
-const (
-	setterUnknown = iota
-	setterNone
-	setterType
-	setterAddr
-)
-
-var setterStyles map[reflect.Type]int
-var setterIface reflect.Type
-var setterMutex sync.RWMutex
-
-func init() {
-	var iface Setter
-	setterIface = reflect.TypeOf(&iface).Elem()
-	setterStyles = make(map[reflect.Type]int)
-}
-
-func setterStyle(outt reflect.Type) int {
-	setterMutex.RLock()
-	style := setterStyles[outt]
-	setterMutex.RUnlock()
-	if style == setterUnknown {
-		setterMutex.Lock()
-		defer setterMutex.Unlock()
-		if outt.Implements(setterIface) {
-			setterStyles[outt] = setterType
-		} else if reflect.PtrTo(outt).Implements(setterIface) {
-			setterStyles[outt] = setterAddr
-		} else {
-			setterStyles[outt] = setterNone
-		}
-		style = setterStyles[outt]
-	}
-	return style
-}
-
-func getSetter(outt reflect.Type, out reflect.Value) Setter {
-	style := setterStyle(outt)
-	if style == setterNone {
-		return nil
-	}
-	if style == setterAddr {
-		if !out.CanAddr() {
-			return nil
-		}
-		out = out.Addr()
-	} else if outt.Kind() == reflect.Ptr && out.IsNil() {
-		out.Set(reflect.New(outt.Elem()))
-	}
-	return out.Interface().(Setter)
-}
-
-func clearMap(m reflect.Value) {
-	var none reflect.Value
-	for _, k := range m.MapKeys() {
-		m.SetMapIndex(k, none)
-	}
-}
-
-func (d *decoder) readDocTo(out reflect.Value) {
-	var elemType reflect.Type
-	outt := out.Type()
-	outk := outt.Kind()
-
-	for {
-		if outk == reflect.Ptr && out.IsNil() {
-			out.Set(reflect.New(outt.Elem()))
-		}
-		if setter := getSetter(outt, out); setter != nil {
-			var raw Raw
-			d.readDocTo(reflect.ValueOf(&raw))
-			err := setter.SetBSON(raw)
-			if _, ok := err.(*TypeError); err != nil && !ok {
-				panic(err)
-			}
-			return
-		}
-		if outk == reflect.Ptr {
-			out = out.Elem()
-			outt = out.Type()
-			outk = out.Kind()
-			continue
-		}
-		break
-	}
-
-	var fieldsMap map[string]fieldInfo
-	var inlineMap reflect.Value
-	start := d.i
-
-	origout := out
-	if outk == reflect.Interface {
-		if d.docType.Kind() == reflect.Map {
-			mv := reflect.MakeMap(d.docType)
-			out.Set(mv)
-			out = mv
-		} else {
-			dv := reflect.New(d.docType).Elem()
-			out.Set(dv)
-			out = dv
-		}
-		outt = out.Type()
-		outk = outt.Kind()
-	}
-
-	docType := d.docType
-	keyType := typeString
-	convertKey := false
-	switch outk {
-	case reflect.Map:
-		keyType = outt.Key()
-		if keyType.Kind() != reflect.String {
-			panic("BSON map must have string keys. Got: " + outt.String())
-		}
-		if keyType != typeString {
-			convertKey = true
-		}
-		elemType = outt.Elem()
-		if elemType == typeIface {
-			d.docType = outt
-		}
-		if out.IsNil() {
-			out.Set(reflect.MakeMap(out.Type()))
-		} else if out.Len() > 0 {
-			clearMap(out)
-		}
-	case reflect.Struct:
-		if outt != typeRaw {
-			sinfo, err := getStructInfo(out.Type())
-			if err != nil {
-				panic(err)
-			}
-			fieldsMap = sinfo.FieldsMap
-			out.Set(sinfo.Zero)
-			if sinfo.InlineMap != -1 {
-				inlineMap = out.Field(sinfo.InlineMap)
-				if !inlineMap.IsNil() && inlineMap.Len() > 0 {
-					clearMap(inlineMap)
-				}
-				elemType = inlineMap.Type().Elem()
-				if elemType == typeIface {
-					d.docType = inlineMap.Type()
-				}
-			}
-		}
-	case reflect.Slice:
-		switch outt.Elem() {
-		case typeDocElem:
-			origout.Set(d.readDocElems(outt))
-			return
-		case typeRawDocElem:
-			origout.Set(d.readRawDocElems(outt))
-			return
-		}
-		fallthrough
-	default:
-		panic("Unsupported document type for unmarshalling: " + out.Type().String())
-	}
-
-	end := int(d.readInt32())
-	end += d.i - 4
-	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
-		corrupted()
-	}
-	for d.in[d.i] != '\x00' {
-		kind := d.readByte()
-		name := d.readCStr()
-		if d.i >= end {
-			corrupted()
-		}
-
-		switch outk {
-		case reflect.Map:
-			e := reflect.New(elemType).Elem()
-			if d.readElemTo(e, kind) {
-				k := reflect.ValueOf(name)
-				if convertKey {
-					k = k.Convert(keyType)
-				}
-				out.SetMapIndex(k, e)
-			}
-		case reflect.Struct:
-			if outt == typeRaw {
-				d.dropElem(kind)
-			} else {
-				if info, ok := fieldsMap[name]; ok {
-					if info.Inline == nil {
-						d.readElemTo(out.Field(info.Num), kind)
-					} else {
-						d.readElemTo(out.FieldByIndex(info.Inline), kind)
-					}
-				} else if inlineMap.IsValid() {
-					if inlineMap.IsNil() {
-						inlineMap.Set(reflect.MakeMap(inlineMap.Type()))
-					}
-					e := reflect.New(elemType).Elem()
-					if d.readElemTo(e, kind) {
-						inlineMap.SetMapIndex(reflect.ValueOf(name), e)
-					}
-				} else {
-					d.dropElem(kind)
-				}
-			}
-		case reflect.Slice:
-		}
-
-		if d.i >= end {
-			corrupted()
-		}
-	}
-	d.i++ // '\x00'
-	if d.i != end {
-		corrupted()
-	}
-	d.docType = docType
-
-	if outt == typeRaw {
-		out.Set(reflect.ValueOf(Raw{0x03, d.in[start:d.i]}))
-	}
-}
-
-func (d *decoder) readArrayDocTo(out reflect.Value) {
-	end := int(d.readInt32())
-	end += d.i - 4
-	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
-		corrupted()
-	}
-	i := 0
-	l := out.Len()
-	for d.in[d.i] != '\x00' {
-		if i >= l {
-			panic("Length mismatch on array field")
-		}
-		kind := d.readByte()
-		for d.i < end && d.in[d.i] != '\x00' {
-			d.i++
-		}
-		if d.i >= end {
-			corrupted()
-		}
-		d.i++
-		d.readElemTo(out.Index(i), kind)
-		if d.i >= end {
-			corrupted()
-		}
-		i++
-	}
-	if i != l {
-		panic("Length mismatch on array field")
-	}
-	d.i++ // '\x00'
-	if d.i != end {
-		corrupted()
-	}
-}
-
-func (d *decoder) readSliceDoc(t reflect.Type) interface{} {
-	tmp := make([]reflect.Value, 0, 8)
-	elemType := t.Elem()
-	if elemType == typeRawDocElem {
-		d.dropElem(0x04)
-		return reflect.Zero(t).Interface()
-	}
-
-	end := int(d.readInt32())
-	end += d.i - 4
-	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
-		corrupted()
-	}
-	for d.in[d.i] != '\x00' {
-		kind := d.readByte()
-		for d.i < end && d.in[d.i] != '\x00' {
-			d.i++
-		}
-		if d.i >= end {
-			corrupted()
-		}
-		d.i++
-		e := reflect.New(elemType).Elem()
-		if d.readElemTo(e, kind) {
-			tmp = append(tmp, e)
-		}
-		if d.i >= end {
-			corrupted()
-		}
-	}
-	d.i++ // '\x00'
-	if d.i != end {
-		corrupted()
-	}
-
-	n := len(tmp)
-	slice := reflect.MakeSlice(t, n, n)
-	for i := 0; i != n; i++ {
-		slice.Index(i).Set(tmp[i])
-	}
-	return slice.Interface()
-}
-
-var typeSlice = reflect.TypeOf([]interface{}{})
-var typeIface = typeSlice.Elem()
-
-func (d *decoder) readDocElems(typ reflect.Type) reflect.Value {
-	docType := d.docType
-	d.docType = typ
-	slice := make([]DocElem, 0, 8)
-	d.readDocWith(func(kind byte, name string) {
-		e := DocElem{Name: name}
-		v := reflect.ValueOf(&e.Value)
-		if d.readElemTo(v.Elem(), kind) {
-			slice = append(slice, e)
-		}
-	})
-	slicev := reflect.New(typ).Elem()
-	slicev.Set(reflect.ValueOf(slice))
-	d.docType = docType
-	return slicev
-}
-
-func (d *decoder) readRawDocElems(typ reflect.Type) reflect.Value {
-	docType := d.docType
-	d.docType = typ
-	slice := make([]RawDocElem, 0, 8)
-	d.readDocWith(func(kind byte, name string) {
-		e := RawDocElem{Name: name}
-		v := reflect.ValueOf(&e.Value)
-		if d.readElemTo(v.Elem(), kind) {
-			slice = append(slice, e)
-		}
-	})
-	slicev := reflect.New(typ).Elem()
-	slicev.Set(reflect.ValueOf(slice))
-	d.docType = docType
-	return slicev
-}
-
-func (d *decoder) readDocWith(f func(kind byte, name string)) {
-	end := int(d.readInt32())
-	end += d.i - 4
-	if end <= d.i || end > len(d.in) || d.in[end-1] != '\x00' {
-		corrupted()
-	}
-	for d.in[d.i] != '\x00' {
-		kind := d.readByte()
-		name := d.readCStr()
-		if d.i >= end {
-			corrupted()
-		}
-		f(kind, name)
-		if d.i >= end {
-			corrupted()
-		}
-	}
-	d.i++ // '\x00'
-	if d.i != end {
-		corrupted()
-	}
-}
-
-// --------------------------------------------------------------------------
-// Unmarshaling of individual elements within a document.
-
-var blackHole = settableValueOf(struct{}{})
-
-func (d *decoder) dropElem(kind byte) {
-	d.readElemTo(blackHole, kind)
-}
-
-// Attempt to decode an element from the document and put it into out.
-// If the types are not compatible, the returned ok value will be
-// false and out will be unchanged.
-func (d *decoder) readElemTo(out reflect.Value, kind byte) (good bool) {
-
-	start := d.i
-
-	if kind == 0x03 {
-		// Delegate unmarshaling of documents.
-		outt := out.Type()
-		outk := out.Kind()
-		switch outk {
-		case reflect.Interface, reflect.Ptr, reflect.Struct, reflect.Map:
-			d.readDocTo(out)
-			return true
-		}
-		if setterStyle(outt) != setterNone {
-			d.readDocTo(out)
-			return true
-		}
-		if outk == reflect.Slice {
-			switch outt.Elem() {
-			case typeDocElem:
-				out.Set(d.readDocElems(outt))
-			case typeRawDocElem:
-				out.Set(d.readRawDocElems(outt))
-			default:
-				d.readDocTo(blackHole)
-			}
-			return true
-		}
-		d.readDocTo(blackHole)
-		return true
-	}
-
-	var in interface{}
-
-	switch kind {
-	case 0x01: // Float64
-		in = d.readFloat64()
-	case 0x02: // UTF-8 string
-		in = d.readStr()
-	case 0x03: // Document
-		panic("Can't happen. Handled above.")
-	case 0x04: // Array
-		outt := out.Type()
-		if setterStyle(outt) != setterNone {
-			// Skip the value so its data is handed to the setter below.
-			d.dropElem(kind)
-			break
-		}
-		for outt.Kind() == reflect.Ptr {
-			outt = outt.Elem()
-		}
-		switch outt.Kind() {
-		case reflect.Array:
-			d.readArrayDocTo(out)
-			return true
-		case reflect.Slice:
-			in = d.readSliceDoc(outt)
-		default:
-			in = d.readSliceDoc(typeSlice)
-		}
-	case 0x05: // Binary
-		b := d.readBinary()
-		if b.Kind == 0x00 || b.Kind == 0x02 {
-			in = b.Data
-		} else {
-			in = b
-		}
-	case 0x06: // Undefined (obsolete, but still seen in the wild)
-		in = Undefined
-	case 0x07: // ObjectId
-		in = ObjectId(d.readBytes(12))
-	case 0x08: // Bool
-		in = d.readBool()
-	case 0x09: // Timestamp
-		// MongoDB handles timestamps as milliseconds.
-		i := d.readInt64()
-		if i == -62135596800000 {
-			in = time.Time{} // In UTC for convenience.
-		} else {
-			in = time.Unix(i/1e3, i%1e3*1e6)
-		}
-	case 0x0A: // Nil
-		in = nil
-	case 0x0B: // RegEx
-		in = d.readRegEx()
-	case 0x0C:
-		in = DBPointer{Namespace: d.readStr(), Id: ObjectId(d.readBytes(12))}
-	case 0x0D: // JavaScript without scope
-		in = JavaScript{Code: d.readStr()}
-	case 0x0E: // Symbol
-		in = Symbol(d.readStr())
-	case 0x0F: // JavaScript with scope
-		d.i += 4 // Skip length
-		js := JavaScript{d.readStr(), make(M)}
-		d.readDocTo(reflect.ValueOf(js.Scope))
-		in = js
-	case 0x10: // Int32
-		in = int(d.readInt32())
-	case 0x11: // Mongo-specific timestamp
-		in = MongoTimestamp(d.readInt64())
-	case 0x12: // Int64
-		in = d.readInt64()
-	case 0x13: // Decimal128
-		in = Decimal128{
-			l: uint64(d.readInt64()),
-			h: uint64(d.readInt64()),
-		}
-	case 0x7F: // Max key
-		in = MaxKey
-	case 0xFF: // Min key
-		in = MinKey
-	default:
-		panic(fmt.Sprintf("Unknown element kind (0x%02X)", kind))
-	}
-
-	outt := out.Type()
-
-	if outt == typeRaw {
-		out.Set(reflect.ValueOf(Raw{kind, d.in[start:d.i]}))
-		return true
-	}
-
-	if setter := getSetter(outt, out); setter != nil {
-		err := setter.SetBSON(Raw{kind, d.in[start:d.i]})
-		if err == SetZero {
-			out.Set(reflect.Zero(outt))
-			return true
-		}
-		if err == nil {
-			return true
-		}
-		if _, ok := err.(*TypeError); !ok {
-			panic(err)
-		}
-		return false
-	}
-
-	if in == nil {
-		out.Set(reflect.Zero(outt))
-		return true
-	}
-
-	outk := outt.Kind()
-
-	// Dereference and initialize pointer if necessary.
-	first := true
-	for outk == reflect.Ptr {
-		if !out.IsNil() {
-			out = out.Elem()
-		} else {
-			elem := reflect.New(outt.Elem())
-			if first {
-				// Only set if value is compatible.
-				first = false
-				defer func(out, elem reflect.Value) {
-					if good {
-						out.Set(elem)
-					}
-				}(out, elem)
-			} else {
-				out.Set(elem)
-			}
-			out = elem
-		}
-		outt = out.Type()
-		outk = outt.Kind()
-	}
-
-	inv := reflect.ValueOf(in)
-	if outt == inv.Type() {
-		out.Set(inv)
-		return true
-	}
-
-	switch outk {
-	case reflect.Interface:
-		out.Set(inv)
-		return true
-	case reflect.String:
-		switch inv.Kind() {
-		case reflect.String:
-			out.SetString(inv.String())
-			return true
-		case reflect.Slice:
-			if b, ok := in.([]byte); ok {
-				out.SetString(string(b))
-				return true
-			}
-		case reflect.Int, reflect.Int64:
-			if outt == typeJSONNumber {
-				out.SetString(strconv.FormatInt(inv.Int(), 10))
-				return true
-			}
-		case reflect.Float64:
-			if outt == typeJSONNumber {
-				out.SetString(strconv.FormatFloat(inv.Float(), 'f', -1, 64))
-				return true
-			}
-		}
-	case reflect.Slice, reflect.Array:
-		// Remember, array (0x04) slices are built with the correct
-		// element type.  If we are here, must be a cross BSON kind
-		// conversion (e.g. 0x05 unmarshalling on string).
-		if outt.Elem().Kind() != reflect.Uint8 {
-			break
-		}
-		switch inv.Kind() {
-		case reflect.String:
-			slice := []byte(inv.String())
-			out.Set(reflect.ValueOf(slice))
-			return true
-		case reflect.Slice:
-			switch outt.Kind() {
-			case reflect.Array:
-				reflect.Copy(out, inv)
-			case reflect.Slice:
-				out.SetBytes(inv.Bytes())
-			}
-			return true
-		}
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		switch inv.Kind() {
-		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-			out.SetInt(inv.Int())
-			return true
-		case reflect.Float32, reflect.Float64:
-			out.SetInt(int64(inv.Float()))
-			return true
-		case reflect.Bool:
-			if inv.Bool() {
-				out.SetInt(1)
-			} else {
-				out.SetInt(0)
-			}
-			return true
-		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-			panic("can't happen: no uint types in BSON (!?)")
-		}
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		switch inv.Kind() {
-		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-			out.SetUint(uint64(inv.Int()))
-			return true
-		case reflect.Float32, reflect.Float64:
-			out.SetUint(uint64(inv.Float()))
-			return true
-		case reflect.Bool:
-			if inv.Bool() {
-				out.SetUint(1)
-			} else {
-				out.SetUint(0)
-			}
-			return true
-		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-			panic("Can't happen. No uint types in BSON.")
-		}
-	case reflect.Float32, reflect.Float64:
-		switch inv.Kind() {
-		case reflect.Float32, reflect.Float64:
-			out.SetFloat(inv.Float())
-			return true
-		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-			out.SetFloat(float64(inv.Int()))
-			return true
-		case reflect.Bool:
-			if inv.Bool() {
-				out.SetFloat(1)
-			} else {
-				out.SetFloat(0)
-			}
-			return true
-		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-			panic("Can't happen. No uint types in BSON?")
-		}
-	case reflect.Bool:
-		switch inv.Kind() {
-		case reflect.Bool:
-			out.SetBool(inv.Bool())
-			return true
-		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-			out.SetBool(inv.Int() != 0)
-			return true
-		case reflect.Float32, reflect.Float64:
-			out.SetBool(inv.Float() != 0)
-			return true
-		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-			panic("Can't happen. No uint types in BSON?")
-		}
-	case reflect.Struct:
-		if outt == typeURL && inv.Kind() == reflect.String {
-			u, err := url.Parse(inv.String())
-			if err != nil {
-				panic(err)
-			}
-			out.Set(reflect.ValueOf(u).Elem())
-			return true
-		}
-		if outt == typeBinary {
-			if b, ok := in.([]byte); ok {
-				out.Set(reflect.ValueOf(Binary{Data: b}))
-				return true
-			}
-		}
-	}
-
-	return false
-}
-
-// --------------------------------------------------------------------------
-// Parsers of basic types.
-
-func (d *decoder) readRegEx() RegEx {
-	re := RegEx{}
-	re.Pattern = d.readCStr()
-	re.Options = d.readCStr()
-	return re
-}
-
-func (d *decoder) readBinary() Binary {
-	l := d.readInt32()
-	b := Binary{}
-	b.Kind = d.readByte()
-	b.Data = d.readBytes(l)
-	if b.Kind == 0x02 && len(b.Data) >= 4 {
-		// Weird obsolete format with redundant length.
-		b.Data = b.Data[4:]
-	}
-	return b
-}
-
-func (d *decoder) readStr() string {
-	l := d.readInt32()
-	b := d.readBytes(l - 1)
-	if d.readByte() != '\x00' {
-		corrupted()
-	}
-	return string(b)
-}
-
-func (d *decoder) readCStr() string {
-	start := d.i
-	end := start
-	l := len(d.in)
-	for ; end != l; end++ {
-		if d.in[end] == '\x00' {
-			break
-		}
-	}
-	d.i = end + 1
-	if d.i > l {
-		corrupted()
-	}
-	return string(d.in[start:end])
-}
-
-func (d *decoder) readBool() bool {
-	b := d.readByte()
-	if b == 0 {
-		return false
-	}
-	if b == 1 {
-		return true
-	}
-	panic(fmt.Sprintf("encoded boolean must be 1 or 0, found %d", b))
-}
-
-func (d *decoder) readFloat64() float64 {
-	return math.Float64frombits(uint64(d.readInt64()))
-}
-
-func (d *decoder) readInt32() int32 {
-	b := d.readBytes(4)
-	return int32((uint32(b[0]) << 0) |
-		(uint32(b[1]) << 8) |
-		(uint32(b[2]) << 16) |
-		(uint32(b[3]) << 24))
-}
-
-func (d *decoder) readInt64() int64 {
-	b := d.readBytes(8)
-	return int64((uint64(b[0]) << 0) |
-		(uint64(b[1]) << 8) |
-		(uint64(b[2]) << 16) |
-		(uint64(b[3]) << 24) |
-		(uint64(b[4]) << 32) |
-		(uint64(b[5]) << 40) |
-		(uint64(b[6]) << 48) |
-		(uint64(b[7]) << 56))
-}
-
-func (d *decoder) readByte() byte {
-	i := d.i
-	d.i++
-	if d.i > len(d.in) {
-		corrupted()
-	}
-	return d.in[i]
-}
-
-func (d *decoder) readBytes(length int32) []byte {
-	if length < 0 {
-		corrupted()
-	}
-	start := d.i
-	d.i += int(length)
-	if d.i < start || d.i > len(d.in) {
-		corrupted()
-	}
-	return d.in[start : start+int(length)]
-}
diff --git a/vendor/gopkg.in/mgo.v2/bson/encode.go b/vendor/gopkg.in/mgo.v2/bson/encode.go
deleted file mode 100644
index add39e8..0000000
--- a/vendor/gopkg.in/mgo.v2/bson/encode.go
+++ /dev/null
@@ -1,514 +0,0 @@
-// BSON library for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-// gobson - BSON library for Go.
-
-package bson
-
-import (
-	"encoding/json"
-	"fmt"
-	"math"
-	"net/url"
-	"reflect"
-	"strconv"
-	"time"
-)
-
-// --------------------------------------------------------------------------
-// Some internal infrastructure.
-
-var (
-	typeBinary         = reflect.TypeOf(Binary{})
-	typeObjectId       = reflect.TypeOf(ObjectId(""))
-	typeDBPointer      = reflect.TypeOf(DBPointer{"", ObjectId("")})
-	typeSymbol         = reflect.TypeOf(Symbol(""))
-	typeMongoTimestamp = reflect.TypeOf(MongoTimestamp(0))
-	typeOrderKey       = reflect.TypeOf(MinKey)
-	typeDocElem        = reflect.TypeOf(DocElem{})
-	typeRawDocElem     = reflect.TypeOf(RawDocElem{})
-	typeRaw            = reflect.TypeOf(Raw{})
-	typeURL            = reflect.TypeOf(url.URL{})
-	typeTime           = reflect.TypeOf(time.Time{})
-	typeString         = reflect.TypeOf("")
-	typeJSONNumber     = reflect.TypeOf(json.Number(""))
-)
-
-const itoaCacheSize = 32
-
-var itoaCache []string
-
-func init() {
-	itoaCache = make([]string, itoaCacheSize)
-	for i := 0; i != itoaCacheSize; i++ {
-		itoaCache[i] = strconv.Itoa(i)
-	}
-}
-
-func itoa(i int) string {
-	if i < itoaCacheSize {
-		return itoaCache[i]
-	}
-	return strconv.Itoa(i)
-}
-
-// --------------------------------------------------------------------------
-// Marshaling of the document value itself.
-
-type encoder struct {
-	out []byte
-}
-
-func (e *encoder) addDoc(v reflect.Value) {
-	for {
-		if vi, ok := v.Interface().(Getter); ok {
-			getv, err := vi.GetBSON()
-			if err != nil {
-				panic(err)
-			}
-			v = reflect.ValueOf(getv)
-			continue
-		}
-		if v.Kind() == reflect.Ptr {
-			v = v.Elem()
-			continue
-		}
-		break
-	}
-
-	if v.Type() == typeRaw {
-		raw := v.Interface().(Raw)
-		if raw.Kind != 0x03 && raw.Kind != 0x00 {
-			panic("Attempted to marshal Raw kind " + strconv.Itoa(int(raw.Kind)) + " as a document")
-		}
-		if len(raw.Data) == 0 {
-			panic("Attempted to marshal empty Raw document")
-		}
-		e.addBytes(raw.Data...)
-		return
-	}
-
-	start := e.reserveInt32()
-
-	switch v.Kind() {
-	case reflect.Map:
-		e.addMap(v)
-	case reflect.Struct:
-		e.addStruct(v)
-	case reflect.Array, reflect.Slice:
-		e.addSlice(v)
-	default:
-		panic("Can't marshal " + v.Type().String() + " as a BSON document")
-	}
-
-	e.addBytes(0)
-	e.setInt32(start, int32(len(e.out)-start))
-}
-
-func (e *encoder) addMap(v reflect.Value) {
-	for _, k := range v.MapKeys() {
-		e.addElem(k.String(), v.MapIndex(k), false)
-	}
-}
-
-func (e *encoder) addStruct(v reflect.Value) {
-	sinfo, err := getStructInfo(v.Type())
-	if err != nil {
-		panic(err)
-	}
-	var value reflect.Value
-	if sinfo.InlineMap >= 0 {
-		m := v.Field(sinfo.InlineMap)
-		if m.Len() > 0 {
-			for _, k := range m.MapKeys() {
-				ks := k.String()
-				if _, found := sinfo.FieldsMap[ks]; found {
-					panic(fmt.Sprintf("Can't have key %q in inlined map; conflicts with struct field", ks))
-				}
-				e.addElem(ks, m.MapIndex(k), false)
-			}
-		}
-	}
-	for _, info := range sinfo.FieldsList {
-		if info.Inline == nil {
-			value = v.Field(info.Num)
-		} else {
-			value = v.FieldByIndex(info.Inline)
-		}
-		if info.OmitEmpty && isZero(value) {
-			continue
-		}
-		e.addElem(info.Key, value, info.MinSize)
-	}
-}
-
-func isZero(v reflect.Value) bool {
-	switch v.Kind() {
-	case reflect.String:
-		return len(v.String()) == 0
-	case reflect.Ptr, reflect.Interface:
-		return v.IsNil()
-	case reflect.Slice:
-		return v.Len() == 0
-	case reflect.Map:
-		return v.Len() == 0
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		return v.Int() == 0
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		return v.Uint() == 0
-	case reflect.Float32, reflect.Float64:
-		return v.Float() == 0
-	case reflect.Bool:
-		return !v.Bool()
-	case reflect.Struct:
-		vt := v.Type()
-		if vt == typeTime {
-			return v.Interface().(time.Time).IsZero()
-		}
-		for i := 0; i < v.NumField(); i++ {
-			if vt.Field(i).PkgPath != "" && !vt.Field(i).Anonymous {
-				continue // Private field
-			}
-			if !isZero(v.Field(i)) {
-				return false
-			}
-		}
-		return true
-	}
-	return false
-}
-
-func (e *encoder) addSlice(v reflect.Value) {
-	vi := v.Interface()
-	if d, ok := vi.(D); ok {
-		for _, elem := range d {
-			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
-		}
-		return
-	}
-	if d, ok := vi.(RawD); ok {
-		for _, elem := range d {
-			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
-		}
-		return
-	}
-	l := v.Len()
-	et := v.Type().Elem()
-	if et == typeDocElem {
-		for i := 0; i < l; i++ {
-			elem := v.Index(i).Interface().(DocElem)
-			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
-		}
-		return
-	}
-	if et == typeRawDocElem {
-		for i := 0; i < l; i++ {
-			elem := v.Index(i).Interface().(RawDocElem)
-			e.addElem(elem.Name, reflect.ValueOf(elem.Value), false)
-		}
-		return
-	}
-	for i := 0; i < l; i++ {
-		e.addElem(itoa(i), v.Index(i), false)
-	}
-}
-
-// --------------------------------------------------------------------------
-// Marshaling of elements in a document.
-
-func (e *encoder) addElemName(kind byte, name string) {
-	e.addBytes(kind)
-	e.addBytes([]byte(name)...)
-	e.addBytes(0)
-}
-
-func (e *encoder) addElem(name string, v reflect.Value, minSize bool) {
-
-	if !v.IsValid() {
-		e.addElemName(0x0A, name)
-		return
-	}
-
-	if getter, ok := v.Interface().(Getter); ok {
-		getv, err := getter.GetBSON()
-		if err != nil {
-			panic(err)
-		}
-		e.addElem(name, reflect.ValueOf(getv), minSize)
-		return
-	}
-
-	switch v.Kind() {
-
-	case reflect.Interface:
-		e.addElem(name, v.Elem(), minSize)
-
-	case reflect.Ptr:
-		e.addElem(name, v.Elem(), minSize)
-
-	case reflect.String:
-		s := v.String()
-		switch v.Type() {
-		case typeObjectId:
-			if len(s) != 12 {
-				panic("ObjectIDs must be exactly 12 bytes long (got " +
-					strconv.Itoa(len(s)) + ")")
-			}
-			e.addElemName(0x07, name)
-			e.addBytes([]byte(s)...)
-		case typeSymbol:
-			e.addElemName(0x0E, name)
-			e.addStr(s)
-		case typeJSONNumber:
-			n := v.Interface().(json.Number)
-			if i, err := n.Int64(); err == nil {
-				e.addElemName(0x12, name)
-				e.addInt64(i)
-			} else if f, err := n.Float64(); err == nil {
-				e.addElemName(0x01, name)
-				e.addFloat64(f)
-			} else {
-				panic("failed to convert json.Number to a number: " + s)
-			}
-		default:
-			e.addElemName(0x02, name)
-			e.addStr(s)
-		}
-
-	case reflect.Float32, reflect.Float64:
-		e.addElemName(0x01, name)
-		e.addFloat64(v.Float())
-
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		u := v.Uint()
-		if int64(u) < 0 {
-			panic("BSON has no uint64 type, and value is too large to fit correctly in an int64")
-		} else if u <= math.MaxInt32 && (minSize || v.Kind() <= reflect.Uint32) {
-			e.addElemName(0x10, name)
-			e.addInt32(int32(u))
-		} else {
-			e.addElemName(0x12, name)
-			e.addInt64(int64(u))
-		}
-
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		switch v.Type() {
-		case typeMongoTimestamp:
-			e.addElemName(0x11, name)
-			e.addInt64(v.Int())
-
-		case typeOrderKey:
-			if v.Int() == int64(MaxKey) {
-				e.addElemName(0x7F, name)
-			} else {
-				e.addElemName(0xFF, name)
-			}
-
-		default:
-			i := v.Int()
-			if (minSize || v.Type().Kind() != reflect.Int64) && i >= math.MinInt32 && i <= math.MaxInt32 {
-				// It fits into an int32, encode as such.
-				e.addElemName(0x10, name)
-				e.addInt32(int32(i))
-			} else {
-				e.addElemName(0x12, name)
-				e.addInt64(i)
-			}
-		}
-
-	case reflect.Bool:
-		e.addElemName(0x08, name)
-		if v.Bool() {
-			e.addBytes(1)
-		} else {
-			e.addBytes(0)
-		}
-
-	case reflect.Map:
-		e.addElemName(0x03, name)
-		e.addDoc(v)
-
-	case reflect.Slice:
-		vt := v.Type()
-		et := vt.Elem()
-		if et.Kind() == reflect.Uint8 {
-			e.addElemName(0x05, name)
-			e.addBinary(0x00, v.Bytes())
-		} else if et == typeDocElem || et == typeRawDocElem {
-			e.addElemName(0x03, name)
-			e.addDoc(v)
-		} else {
-			e.addElemName(0x04, name)
-			e.addDoc(v)
-		}
-
-	case reflect.Array:
-		et := v.Type().Elem()
-		if et.Kind() == reflect.Uint8 {
-			e.addElemName(0x05, name)
-			if v.CanAddr() {
-				e.addBinary(0x00, v.Slice(0, v.Len()).Interface().([]byte))
-			} else {
-				n := v.Len()
-				e.addInt32(int32(n))
-				e.addBytes(0x00)
-				for i := 0; i < n; i++ {
-					el := v.Index(i)
-					e.addBytes(byte(el.Uint()))
-				}
-			}
-		} else {
-			e.addElemName(0x04, name)
-			e.addDoc(v)
-		}
-
-	case reflect.Struct:
-		switch s := v.Interface().(type) {
-
-		case Raw:
-			kind := s.Kind
-			if kind == 0x00 {
-				kind = 0x03
-			}
-			if len(s.Data) == 0 && kind != 0x06 && kind != 0x0A && kind != 0xFF && kind != 0x7F {
-				panic("Attempted to marshal empty Raw document")
-			}
-			e.addElemName(kind, name)
-			e.addBytes(s.Data...)
-
-		case Binary:
-			e.addElemName(0x05, name)
-			e.addBinary(s.Kind, s.Data)
-
-		case Decimal128:
-			e.addElemName(0x13, name)
-			e.addInt64(int64(s.l))
-			e.addInt64(int64(s.h))
-
-		case DBPointer:
-			e.addElemName(0x0C, name)
-			e.addStr(s.Namespace)
-			if len(s.Id) != 12 {
-				panic("ObjectIDs must be exactly 12 bytes long (got " +
-					strconv.Itoa(len(s.Id)) + ")")
-			}
-			e.addBytes([]byte(s.Id)...)
-
-		case RegEx:
-			e.addElemName(0x0B, name)
-			e.addCStr(s.Pattern)
-			e.addCStr(s.Options)
-
-		case JavaScript:
-			if s.Scope == nil {
-				e.addElemName(0x0D, name)
-				e.addStr(s.Code)
-			} else {
-				e.addElemName(0x0F, name)
-				start := e.reserveInt32()
-				e.addStr(s.Code)
-				e.addDoc(reflect.ValueOf(s.Scope))
-				e.setInt32(start, int32(len(e.out)-start))
-			}
-
-		case time.Time:
-			// MongoDB handles timestamps as milliseconds.
-			e.addElemName(0x09, name)
-			e.addInt64(s.Unix()*1000 + int64(s.Nanosecond()/1e6))
-
-		case url.URL:
-			e.addElemName(0x02, name)
-			e.addStr(s.String())
-
-		case undefined:
-			e.addElemName(0x06, name)
-
-		default:
-			e.addElemName(0x03, name)
-			e.addDoc(v)
-		}
-
-	default:
-		panic("Can't marshal " + v.Type().String() + " in a BSON document")
-	}
-}
-
-// --------------------------------------------------------------------------
-// Marshaling of base types.
-
-func (e *encoder) addBinary(subtype byte, v []byte) {
-	if subtype == 0x02 {
-		// Wonder how that brilliant idea came to life. Obsolete, luckily.
-		e.addInt32(int32(len(v) + 4))
-		e.addBytes(subtype)
-		e.addInt32(int32(len(v)))
-	} else {
-		e.addInt32(int32(len(v)))
-		e.addBytes(subtype)
-	}
-	e.addBytes(v...)
-}
-
-func (e *encoder) addStr(v string) {
-	e.addInt32(int32(len(v) + 1))
-	e.addCStr(v)
-}
-
-func (e *encoder) addCStr(v string) {
-	e.addBytes([]byte(v)...)
-	e.addBytes(0)
-}
-
-func (e *encoder) reserveInt32() (pos int) {
-	pos = len(e.out)
-	e.addBytes(0, 0, 0, 0)
-	return pos
-}
-
-func (e *encoder) setInt32(pos int, v int32) {
-	e.out[pos+0] = byte(v)
-	e.out[pos+1] = byte(v >> 8)
-	e.out[pos+2] = byte(v >> 16)
-	e.out[pos+3] = byte(v >> 24)
-}
-
-func (e *encoder) addInt32(v int32) {
-	u := uint32(v)
-	e.addBytes(byte(u), byte(u>>8), byte(u>>16), byte(u>>24))
-}
-
-func (e *encoder) addInt64(v int64) {
-	u := uint64(v)
-	e.addBytes(byte(u), byte(u>>8), byte(u>>16), byte(u>>24),
-		byte(u>>32), byte(u>>40), byte(u>>48), byte(u>>56))
-}
-
-func (e *encoder) addFloat64(v float64) {
-	e.addInt64(int64(math.Float64bits(v)))
-}
-
-func (e *encoder) addBytes(v ...byte) {
-	e.out = append(e.out, v...)
-}
diff --git a/vendor/gopkg.in/mgo.v2/bson/json.go b/vendor/gopkg.in/mgo.v2/bson/json.go
deleted file mode 100644
index 09df826..0000000
--- a/vendor/gopkg.in/mgo.v2/bson/json.go
+++ /dev/null
@@ -1,380 +0,0 @@
-package bson
-
-import (
-	"bytes"
-	"encoding/base64"
-	"fmt"
-	"gopkg.in/mgo.v2/internal/json"
-	"strconv"
-	"time"
-)
-
-// UnmarshalJSON unmarshals a JSON value that may hold non-standard
-// syntax as defined in BSON's extended JSON specification.
-func UnmarshalJSON(data []byte, value interface{}) error {
-	d := json.NewDecoder(bytes.NewBuffer(data))
-	d.Extend(&jsonExt)
-	return d.Decode(value)
-}
-
-// MarshalJSON marshals a JSON value that may hold non-standard
-// syntax as defined in BSON's extended JSON specification.
-func MarshalJSON(value interface{}) ([]byte, error) {
-	var buf bytes.Buffer
-	e := json.NewEncoder(&buf)
-	e.Extend(&jsonExt)
-	err := e.Encode(value)
-	if err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
-}
-
-// jdec is used internally by the JSON decoding functions
-// so they may unmarshal functions without getting into endless
-// recursion due to keyed objects.
-func jdec(data []byte, value interface{}) error {
-	d := json.NewDecoder(bytes.NewBuffer(data))
-	d.Extend(&funcExt)
-	return d.Decode(value)
-}
-
-var jsonExt json.Extension
-var funcExt json.Extension
-
-// TODO
-// - Shell regular expressions ("/regexp/opts")
-
-func init() {
-	jsonExt.DecodeUnquotedKeys(true)
-	jsonExt.DecodeTrailingCommas(true)
-
-	funcExt.DecodeFunc("BinData", "$binaryFunc", "$type", "$binary")
-	jsonExt.DecodeKeyed("$binary", jdecBinary)
-	jsonExt.DecodeKeyed("$binaryFunc", jdecBinary)
-	jsonExt.EncodeType([]byte(nil), jencBinarySlice)
-	jsonExt.EncodeType(Binary{}, jencBinaryType)
-
-	funcExt.DecodeFunc("ISODate", "$dateFunc", "S")
-	funcExt.DecodeFunc("new Date", "$dateFunc", "S")
-	jsonExt.DecodeKeyed("$date", jdecDate)
-	jsonExt.DecodeKeyed("$dateFunc", jdecDate)
-	jsonExt.EncodeType(time.Time{}, jencDate)
-
-	funcExt.DecodeFunc("Timestamp", "$timestamp", "t", "i")
-	jsonExt.DecodeKeyed("$timestamp", jdecTimestamp)
-	jsonExt.EncodeType(MongoTimestamp(0), jencTimestamp)
-
-	funcExt.DecodeConst("undefined", Undefined)
-
-	jsonExt.DecodeKeyed("$regex", jdecRegEx)
-	jsonExt.EncodeType(RegEx{}, jencRegEx)
-
-	funcExt.DecodeFunc("ObjectId", "$oidFunc", "Id")
-	jsonExt.DecodeKeyed("$oid", jdecObjectId)
-	jsonExt.DecodeKeyed("$oidFunc", jdecObjectId)
-	jsonExt.EncodeType(ObjectId(""), jencObjectId)
-
-	funcExt.DecodeFunc("DBRef", "$dbrefFunc", "$ref", "$id")
-	jsonExt.DecodeKeyed("$dbrefFunc", jdecDBRef)
-
-	funcExt.DecodeFunc("NumberLong", "$numberLongFunc", "N")
-	jsonExt.DecodeKeyed("$numberLong", jdecNumberLong)
-	jsonExt.DecodeKeyed("$numberLongFunc", jdecNumberLong)
-	jsonExt.EncodeType(int64(0), jencNumberLong)
-	jsonExt.EncodeType(int(0), jencInt)
-
-	funcExt.DecodeConst("MinKey", MinKey)
-	funcExt.DecodeConst("MaxKey", MaxKey)
-	jsonExt.DecodeKeyed("$minKey", jdecMinKey)
-	jsonExt.DecodeKeyed("$maxKey", jdecMaxKey)
-	jsonExt.EncodeType(orderKey(0), jencMinMaxKey)
-
-	jsonExt.DecodeKeyed("$undefined", jdecUndefined)
-	jsonExt.EncodeType(Undefined, jencUndefined)
-
-	jsonExt.Extend(&funcExt)
-}
-
-func fbytes(format string, args ...interface{}) []byte {
-	var buf bytes.Buffer
-	fmt.Fprintf(&buf, format, args...)
-	return buf.Bytes()
-}
-
-func jdecBinary(data []byte) (interface{}, error) {
-	var v struct {
-		Binary []byte `json:"$binary"`
-		Type   string `json:"$type"`
-		Func   struct {
-			Binary []byte `json:"$binary"`
-			Type   int64  `json:"$type"`
-		} `json:"$binaryFunc"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-
-	var binData []byte
-	var binKind int64
-	if v.Type == "" && v.Binary == nil {
-		binData = v.Func.Binary
-		binKind = v.Func.Type
-	} else if v.Type == "" {
-		return v.Binary, nil
-	} else {
-		binData = v.Binary
-		binKind, err = strconv.ParseInt(v.Type, 0, 64)
-		if err != nil {
-			binKind = -1
-		}
-	}
-
-	if binKind == 0 {
-		return binData, nil
-	}
-	if binKind < 0 || binKind > 255 {
-		return nil, fmt.Errorf("invalid type in binary object: %s", data)
-	}
-
-	return Binary{Kind: byte(binKind), Data: binData}, nil
-}
-
-func jencBinarySlice(v interface{}) ([]byte, error) {
-	in := v.([]byte)
-	out := make([]byte, base64.StdEncoding.EncodedLen(len(in)))
-	base64.StdEncoding.Encode(out, in)
-	return fbytes(`{"$binary":"%s","$type":"0x0"}`, out), nil
-}
-
-func jencBinaryType(v interface{}) ([]byte, error) {
-	in := v.(Binary)
-	out := make([]byte, base64.StdEncoding.EncodedLen(len(in.Data)))
-	base64.StdEncoding.Encode(out, in.Data)
-	return fbytes(`{"$binary":"%s","$type":"0x%x"}`, out, in.Kind), nil
-}
-
-const jdateFormat = "2006-01-02T15:04:05.999Z"
-
-func jdecDate(data []byte) (interface{}, error) {
-	var v struct {
-		S    string `json:"$date"`
-		Func struct {
-			S string
-		} `json:"$dateFunc"`
-	}
-	_ = jdec(data, &v)
-	if v.S == "" {
-		v.S = v.Func.S
-	}
-	if v.S != "" {
-		for _, format := range []string{jdateFormat, "2006-01-02"} {
-			t, err := time.Parse(format, v.S)
-			if err == nil {
-				return t, nil
-			}
-		}
-		return nil, fmt.Errorf("cannot parse date: %q", v.S)
-	}
-
-	var vn struct {
-		Date struct {
-			N int64 `json:"$numberLong,string"`
-		} `json:"$date"`
-		Func struct {
-			S int64
-		} `json:"$dateFunc"`
-	}
-	err := jdec(data, &vn)
-	if err != nil {
-		return nil, fmt.Errorf("cannot parse date: %q", data)
-	}
-	n := vn.Date.N
-	if n == 0 {
-		n = vn.Func.S
-	}
-	return time.Unix(n/1000, n%1000*1e6).UTC(), nil
-}
-
-func jencDate(v interface{}) ([]byte, error) {
-	t := v.(time.Time)
-	return fbytes(`{"$date":%q}`, t.Format(jdateFormat)), nil
-}
-
-func jdecTimestamp(data []byte) (interface{}, error) {
-	var v struct {
-		Func struct {
-			T int32 `json:"t"`
-			I int32 `json:"i"`
-		} `json:"$timestamp"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-	return MongoTimestamp(uint64(v.Func.T)<<32 | uint64(uint32(v.Func.I))), nil
-}
-
-func jencTimestamp(v interface{}) ([]byte, error) {
-	ts := uint64(v.(MongoTimestamp))
-	return fbytes(`{"$timestamp":{"t":%d,"i":%d}}`, ts>>32, uint32(ts)), nil
-}
-
-func jdecRegEx(data []byte) (interface{}, error) {
-	var v struct {
-		Regex   string `json:"$regex"`
-		Options string `json:"$options"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-	return RegEx{v.Regex, v.Options}, nil
-}
-
-func jencRegEx(v interface{}) ([]byte, error) {
-	re := v.(RegEx)
-	type regex struct {
-		Regex   string `json:"$regex"`
-		Options string `json:"$options"`
-	}
-	return json.Marshal(regex{re.Pattern, re.Options})
-}
-
-func jdecObjectId(data []byte) (interface{}, error) {
-	var v struct {
-		Id   string `json:"$oid"`
-		Func struct {
-			Id string
-		} `json:"$oidFunc"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-	if v.Id == "" {
-		v.Id = v.Func.Id
-	}
-	return ObjectIdHex(v.Id), nil
-}
-
-func jencObjectId(v interface{}) ([]byte, error) {
-	return fbytes(`{"$oid":"%s"}`, v.(ObjectId).Hex()), nil
-}
-
-func jdecDBRef(data []byte) (interface{}, error) {
-	// TODO Support unmarshaling $ref and $id into the input value.
-	var v struct {
-		Obj map[string]interface{} `json:"$dbrefFunc"`
-	}
-	// TODO Fix this. Must not be required.
-	v.Obj = make(map[string]interface{})
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-	return v.Obj, nil
-}
-
-func jdecNumberLong(data []byte) (interface{}, error) {
-	var v struct {
-		N    int64 `json:"$numberLong,string"`
-		Func struct {
-			N int64 `json:",string"`
-		} `json:"$numberLongFunc"`
-	}
-	var vn struct {
-		N    int64 `json:"$numberLong"`
-		Func struct {
-			N int64
-		} `json:"$numberLongFunc"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		err = jdec(data, &vn)
-		v.N = vn.N
-		v.Func.N = vn.Func.N
-	}
-	if err != nil {
-		return nil, err
-	}
-	if v.N != 0 {
-		return v.N, nil
-	}
-	return v.Func.N, nil
-}
-
-func jencNumberLong(v interface{}) ([]byte, error) {
-	n := v.(int64)
-	f := `{"$numberLong":"%d"}`
-	if n <= 1<<53 {
-		f = `{"$numberLong":%d}`
-	}
-	return fbytes(f, n), nil
-}
-
-func jencInt(v interface{}) ([]byte, error) {
-	n := v.(int)
-	f := `{"$numberLong":"%d"}`
-	if int64(n) <= 1<<53 {
-		f = `%d`
-	}
-	return fbytes(f, n), nil
-}
-
-func jdecMinKey(data []byte) (interface{}, error) {
-	var v struct {
-		N int64 `json:"$minKey"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-	if v.N != 1 {
-		return nil, fmt.Errorf("invalid $minKey object: %s", data)
-	}
-	return MinKey, nil
-}
-
-func jdecMaxKey(data []byte) (interface{}, error) {
-	var v struct {
-		N int64 `json:"$maxKey"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-	if v.N != 1 {
-		return nil, fmt.Errorf("invalid $maxKey object: %s", data)
-	}
-	return MaxKey, nil
-}
-
-func jencMinMaxKey(v interface{}) ([]byte, error) {
-	switch v.(orderKey) {
-	case MinKey:
-		return []byte(`{"$minKey":1}`), nil
-	case MaxKey:
-		return []byte(`{"$maxKey":1}`), nil
-	}
-	panic(fmt.Sprintf("invalid $minKey/$maxKey value: %d", v))
-}
-
-func jdecUndefined(data []byte) (interface{}, error) {
-	var v struct {
-		B bool `json:"$undefined"`
-	}
-	err := jdec(data, &v)
-	if err != nil {
-		return nil, err
-	}
-	if !v.B {
-		return nil, fmt.Errorf("invalid $undefined object: %s", data)
-	}
-	return Undefined, nil
-}
-
-func jencUndefined(v interface{}) ([]byte, error) {
-	return []byte(`{"$undefined":true}`), nil
-}
diff --git a/vendor/gopkg.in/mgo.v2/bulk.go b/vendor/gopkg.in/mgo.v2/bulk.go
deleted file mode 100644
index 072a520..0000000
--- a/vendor/gopkg.in/mgo.v2/bulk.go
+++ /dev/null
@@ -1,351 +0,0 @@
-package mgo
-
-import (
-	"bytes"
-	"sort"
-
-	"gopkg.in/mgo.v2/bson"
-)
-
-// Bulk represents an operation that can be prepared with several
-// orthogonal changes before being delivered to the server.
-//
-// MongoDB servers older than version 2.6 do not have proper support for bulk
-// operations, so the driver attempts to map its API as much as possible into
-// the functionality that works. In particular, in those releases updates and
-// removals are sent individually, and inserts are sent in bulk but have
-// suboptimal error reporting compared to more recent versions of the server.
-// See the documentation of BulkErrorCase for details on that.
-//
-// Relevant documentation:
-//
-//   http://blog.mongodb.org/post/84922794768/mongodbs-new-bulk-api
-//
-type Bulk struct {
-	c       *Collection
-	opcount int
-	actions []bulkAction
-	ordered bool
-}
-
-type bulkOp int
-
-const (
-	bulkInsert bulkOp = iota + 1
-	bulkUpdate
-	bulkUpdateAll
-	bulkRemove
-)
-
-type bulkAction struct {
-	op   bulkOp
-	docs []interface{}
-	idxs []int
-}
-
-type bulkUpdateOp []interface{}
-type bulkDeleteOp []interface{}
-
-// BulkResult holds the results for a bulk operation.
-type BulkResult struct {
-	Matched  int
-	Modified int // Available only for MongoDB 2.6+
-
-	// Be conservative while we understand exactly how to report these
-	// results in a useful and convenient way, and also how to emulate
-	// them with prior servers.
-	private bool
-}
-
-// BulkError holds an error returned from running a Bulk operation.
-// Individual errors may be obtained and inspected via the Cases method.
-type BulkError struct {
-	ecases []BulkErrorCase
-}
-
-func (e *BulkError) Error() string {
-	if len(e.ecases) == 0 {
-		return "invalid BulkError instance: no errors"
-	}
-	if len(e.ecases) == 1 {
-		return e.ecases[0].Err.Error()
-	}
-	msgs := make([]string, 0, len(e.ecases))
-	seen := make(map[string]bool)
-	for _, ecase := range e.ecases {
-		msg := ecase.Err.Error()
-		if !seen[msg] {
-			seen[msg] = true
-			msgs = append(msgs, msg)
-		}
-	}
-	if len(msgs) == 1 {
-		return msgs[0]
-	}
-	var buf bytes.Buffer
-	buf.WriteString("multiple errors in bulk operation:\n")
-	for _, msg := range msgs {
-		buf.WriteString("  - ")
-		buf.WriteString(msg)
-		buf.WriteByte('\n')
-	}
-	return buf.String()
-}
-
-type bulkErrorCases []BulkErrorCase
-
-func (slice bulkErrorCases) Len() int           { return len(slice) }
-func (slice bulkErrorCases) Less(i, j int) bool { return slice[i].Index < slice[j].Index }
-func (slice bulkErrorCases) Swap(i, j int)      { slice[i], slice[j] = slice[j], slice[i] }
-
-// BulkErrorCase holds an individual error found while attempting a single change
-// within a bulk operation, and the position in which it was enqueued.
-//
-// MongoDB servers older than version 2.6 do not have proper support for bulk
-// operations, so the driver attempts to map its API as much as possible into
-// the functionality that works. In particular, only the last error is reported
-// for bulk inserts and without any positional information, so the Index
-// field is set to -1 in these cases.
-type BulkErrorCase struct {
-	Index int // Position of operation that failed, or -1 if unknown.
-	Err   error
-}
-
-// Cases returns all individual errors found while attempting the requested changes.
-//
-// See the documentation of BulkErrorCase for limitations in older MongoDB releases.
-func (e *BulkError) Cases() []BulkErrorCase {
-	return e.ecases
-}
-
-// Bulk returns a value to prepare the execution of a bulk operation.
-func (c *Collection) Bulk() *Bulk {
-	return &Bulk{c: c, ordered: true}
-}
-
-// Unordered puts the bulk operation in unordered mode.
-//
-// In unordered mode the indvidual operations may be sent
-// out of order, which means latter operations may proceed
-// even if prior ones have failed.
-func (b *Bulk) Unordered() {
-	b.ordered = false
-}
-
-func (b *Bulk) action(op bulkOp, opcount int) *bulkAction {
-	var action *bulkAction
-	if len(b.actions) > 0 && b.actions[len(b.actions)-1].op == op {
-		action = &b.actions[len(b.actions)-1]
-	} else if !b.ordered {
-		for i := range b.actions {
-			if b.actions[i].op == op {
-				action = &b.actions[i]
-				break
-			}
-		}
-	}
-	if action == nil {
-		b.actions = append(b.actions, bulkAction{op: op})
-		action = &b.actions[len(b.actions)-1]
-	}
-	for i := 0; i < opcount; i++ {
-		action.idxs = append(action.idxs, b.opcount)
-		b.opcount++
-	}
-	return action
-}
-
-// Insert queues up the provided documents for insertion.
-func (b *Bulk) Insert(docs ...interface{}) {
-	action := b.action(bulkInsert, len(docs))
-	action.docs = append(action.docs, docs...)
-}
-
-// Remove queues up the provided selectors for removing matching documents.
-// Each selector will remove only a single matching document.
-func (b *Bulk) Remove(selectors ...interface{}) {
-	action := b.action(bulkRemove, len(selectors))
-	for _, selector := range selectors {
-		if selector == nil {
-			selector = bson.D{}
-		}
-		action.docs = append(action.docs, &deleteOp{
-			Collection: b.c.FullName,
-			Selector:   selector,
-			Flags:      1,
-			Limit:      1,
-		})
-	}
-}
-
-// RemoveAll queues up the provided selectors for removing all matching documents.
-// Each selector will remove all matching documents.
-func (b *Bulk) RemoveAll(selectors ...interface{}) {
-	action := b.action(bulkRemove, len(selectors))
-	for _, selector := range selectors {
-		if selector == nil {
-			selector = bson.D{}
-		}
-		action.docs = append(action.docs, &deleteOp{
-			Collection: b.c.FullName,
-			Selector:   selector,
-			Flags:      0,
-			Limit:      0,
-		})
-	}
-}
-
-// Update queues up the provided pairs of updating instructions.
-// The first element of each pair selects which documents must be
-// updated, and the second element defines how to update it.
-// Each pair matches exactly one document for updating at most.
-func (b *Bulk) Update(pairs ...interface{}) {
-	if len(pairs)%2 != 0 {
-		panic("Bulk.Update requires an even number of parameters")
-	}
-	action := b.action(bulkUpdate, len(pairs)/2)
-	for i := 0; i < len(pairs); i += 2 {
-		selector := pairs[i]
-		if selector == nil {
-			selector = bson.D{}
-		}
-		action.docs = append(action.docs, &updateOp{
-			Collection: b.c.FullName,
-			Selector:   selector,
-			Update:     pairs[i+1],
-		})
-	}
-}
-
-// UpdateAll queues up the provided pairs of updating instructions.
-// The first element of each pair selects which documents must be
-// updated, and the second element defines how to update it.
-// Each pair updates all documents matching the selector.
-func (b *Bulk) UpdateAll(pairs ...interface{}) {
-	if len(pairs)%2 != 0 {
-		panic("Bulk.UpdateAll requires an even number of parameters")
-	}
-	action := b.action(bulkUpdate, len(pairs)/2)
-	for i := 0; i < len(pairs); i += 2 {
-		selector := pairs[i]
-		if selector == nil {
-			selector = bson.D{}
-		}
-		action.docs = append(action.docs, &updateOp{
-			Collection: b.c.FullName,
-			Selector:   selector,
-			Update:     pairs[i+1],
-			Flags:      2,
-			Multi:      true,
-		})
-	}
-}
-
-// Upsert queues up the provided pairs of upserting instructions.
-// The first element of each pair selects which documents must be
-// updated, and the second element defines how to update it.
-// Each pair matches exactly one document for updating at most.
-func (b *Bulk) Upsert(pairs ...interface{}) {
-	if len(pairs)%2 != 0 {
-		panic("Bulk.Update requires an even number of parameters")
-	}
-	action := b.action(bulkUpdate, len(pairs)/2)
-	for i := 0; i < len(pairs); i += 2 {
-		selector := pairs[i]
-		if selector == nil {
-			selector = bson.D{}
-		}
-		action.docs = append(action.docs, &updateOp{
-			Collection: b.c.FullName,
-			Selector:   selector,
-			Update:     pairs[i+1],
-			Flags:      1,
-			Upsert:     true,
-		})
-	}
-}
-
-// Run runs all the operations queued up.
-//
-// If an error is reported on an unordered bulk operation, the error value may
-// be an aggregation of all issues observed. As an exception to that, Insert
-// operations running on MongoDB versions prior to 2.6 will report the last
-// error only due to a limitation in the wire protocol.
-func (b *Bulk) Run() (*BulkResult, error) {
-	var result BulkResult
-	var berr BulkError
-	var failed bool
-	for i := range b.actions {
-		action := &b.actions[i]
-		var ok bool
-		switch action.op {
-		case bulkInsert:
-			ok = b.runInsert(action, &result, &berr)
-		case bulkUpdate:
-			ok = b.runUpdate(action, &result, &berr)
-		case bulkRemove:
-			ok = b.runRemove(action, &result, &berr)
-		default:
-			panic("unknown bulk operation")
-		}
-		if !ok {
-			failed = true
-			if b.ordered {
-				break
-			}
-		}
-	}
-	if failed {
-		sort.Sort(bulkErrorCases(berr.ecases))
-		return nil, &berr
-	}
-	return &result, nil
-}
-
-func (b *Bulk) runInsert(action *bulkAction, result *BulkResult, berr *BulkError) bool {
-	op := &insertOp{b.c.FullName, action.docs, 0}
-	if !b.ordered {
-		op.flags = 1 // ContinueOnError
-	}
-	lerr, err := b.c.writeOp(op, b.ordered)
-	return b.checkSuccess(action, berr, lerr, err)
-}
-
-func (b *Bulk) runUpdate(action *bulkAction, result *BulkResult, berr *BulkError) bool {
-	lerr, err := b.c.writeOp(bulkUpdateOp(action.docs), b.ordered)
-	if lerr != nil {
-		result.Matched += lerr.N
-		result.Modified += lerr.modified
-	}
-	return b.checkSuccess(action, berr, lerr, err)
-}
-
-func (b *Bulk) runRemove(action *bulkAction, result *BulkResult, berr *BulkError) bool {
-	lerr, err := b.c.writeOp(bulkDeleteOp(action.docs), b.ordered)
-	if lerr != nil {
-		result.Matched += lerr.N
-		result.Modified += lerr.modified
-	}
-	return b.checkSuccess(action, berr, lerr, err)
-}
-
-func (b *Bulk) checkSuccess(action *bulkAction, berr *BulkError, lerr *LastError, err error) bool {
-	if lerr != nil && len(lerr.ecases) > 0 {
-		for i := 0; i < len(lerr.ecases); i++ {
-			// Map back from the local error index into the visible one.
-			ecase := lerr.ecases[i]
-			idx := ecase.Index
-			if idx >= 0 {
-				idx = action.idxs[idx]
-			}
-			berr.ecases = append(berr.ecases, BulkErrorCase{idx, ecase.Err})
-		}
-		return false
-	} else if err != nil {
-		for i := 0; i < len(action.idxs); i++ {
-			berr.ecases = append(berr.ecases, BulkErrorCase{action.idxs[i], err})
-		}
-		return false
-	}
-	return true
-}
diff --git a/vendor/gopkg.in/mgo.v2/cluster.go b/vendor/gopkg.in/mgo.v2/cluster.go
deleted file mode 100644
index c3bf8b0..0000000
--- a/vendor/gopkg.in/mgo.v2/cluster.go
+++ /dev/null
@@ -1,682 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"errors"
-	"fmt"
-	"net"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"gopkg.in/mgo.v2/bson"
-)
-
-// ---------------------------------------------------------------------------
-// Mongo cluster encapsulation.
-//
-// A cluster enables the communication with one or more servers participating
-// in a mongo cluster.  This works with individual servers, a replica set,
-// a replica pair, one or multiple mongos routers, etc.
-
-type mongoCluster struct {
-	sync.RWMutex
-	serverSynced sync.Cond
-	userSeeds    []string
-	dynaSeeds    []string
-	servers      mongoServers
-	masters      mongoServers
-	references   int
-	syncing      bool
-	direct       bool
-	failFast     bool
-	syncCount    uint
-	setName      string
-	cachedIndex  map[string]bool
-	sync         chan bool
-	dial         dialer
-}
-
-func newCluster(userSeeds []string, direct, failFast bool, dial dialer, setName string) *mongoCluster {
-	cluster := &mongoCluster{
-		userSeeds:  userSeeds,
-		references: 1,
-		direct:     direct,
-		failFast:   failFast,
-		dial:       dial,
-		setName:    setName,
-	}
-	cluster.serverSynced.L = cluster.RWMutex.RLocker()
-	cluster.sync = make(chan bool, 1)
-	stats.cluster(+1)
-	go cluster.syncServersLoop()
-	return cluster
-}
-
-// Acquire increases the reference count for the cluster.
-func (cluster *mongoCluster) Acquire() {
-	cluster.Lock()
-	cluster.references++
-	debugf("Cluster %p acquired (refs=%d)", cluster, cluster.references)
-	cluster.Unlock()
-}
-
-// Release decreases the reference count for the cluster. Once
-// it reaches zero, all servers will be closed.
-func (cluster *mongoCluster) Release() {
-	cluster.Lock()
-	if cluster.references == 0 {
-		panic("cluster.Release() with references == 0")
-	}
-	cluster.references--
-	debugf("Cluster %p released (refs=%d)", cluster, cluster.references)
-	if cluster.references == 0 {
-		for _, server := range cluster.servers.Slice() {
-			server.Close()
-		}
-		// Wake up the sync loop so it can die.
-		cluster.syncServers()
-		stats.cluster(-1)
-	}
-	cluster.Unlock()
-}
-
-func (cluster *mongoCluster) LiveServers() (servers []string) {
-	cluster.RLock()
-	for _, serv := range cluster.servers.Slice() {
-		servers = append(servers, serv.Addr)
-	}
-	cluster.RUnlock()
-	return servers
-}
-
-func (cluster *mongoCluster) removeServer(server *mongoServer) {
-	cluster.Lock()
-	cluster.masters.Remove(server)
-	other := cluster.servers.Remove(server)
-	cluster.Unlock()
-	if other != nil {
-		other.Close()
-		log("Removed server ", server.Addr, " from cluster.")
-	}
-	server.Close()
-}
-
-type isMasterResult struct {
-	IsMaster       bool
-	Secondary      bool
-	Primary        string
-	Hosts          []string
-	Passives       []string
-	Tags           bson.D
-	Msg            string
-	SetName        string `bson:"setName"`
-	MaxWireVersion int    `bson:"maxWireVersion"`
-}
-
-func (cluster *mongoCluster) isMaster(socket *mongoSocket, result *isMasterResult) error {
-	// Monotonic let's it talk to a slave and still hold the socket.
-	session := newSession(Monotonic, cluster, 10*time.Second)
-	session.setSocket(socket)
-	err := session.Run("ismaster", result)
-	session.Close()
-	return err
-}
-
-type possibleTimeout interface {
-	Timeout() bool
-}
-
-var syncSocketTimeout = 5 * time.Second
-
-func (cluster *mongoCluster) syncServer(server *mongoServer) (info *mongoServerInfo, hosts []string, err error) {
-	var syncTimeout time.Duration
-	if raceDetector {
-		// This variable is only ever touched by tests.
-		globalMutex.Lock()
-		syncTimeout = syncSocketTimeout
-		globalMutex.Unlock()
-	} else {
-		syncTimeout = syncSocketTimeout
-	}
-
-	addr := server.Addr
-	log("SYNC Processing ", addr, "...")
-
-	// Retry a few times to avoid knocking a server down for a hiccup.
-	var result isMasterResult
-	var tryerr error
-	for retry := 0; ; retry++ {
-		if retry == 3 || retry == 1 && cluster.failFast {
-			return nil, nil, tryerr
-		}
-		if retry > 0 {
-			// Don't abuse the server needlessly if there's something actually wrong.
-			if err, ok := tryerr.(possibleTimeout); ok && err.Timeout() {
-				// Give a chance for waiters to timeout as well.
-				cluster.serverSynced.Broadcast()
-			}
-			time.Sleep(syncShortDelay)
-		}
-
-		// It's not clear what would be a good timeout here. Is it
-		// better to wait longer or to retry?
-		socket, _, err := server.AcquireSocket(0, syncTimeout)
-		if err != nil {
-			tryerr = err
-			logf("SYNC Failed to get socket to %s: %v", addr, err)
-			continue
-		}
-		err = cluster.isMaster(socket, &result)
-		socket.Release()
-		if err != nil {
-			tryerr = err
-			logf("SYNC Command 'ismaster' to %s failed: %v", addr, err)
-			continue
-		}
-		debugf("SYNC Result of 'ismaster' from %s: %#v", addr, result)
-		break
-	}
-
-	if cluster.setName != "" && result.SetName != cluster.setName {
-		logf("SYNC Server %s is not a member of replica set %q", addr, cluster.setName)
-		return nil, nil, fmt.Errorf("server %s is not a member of replica set %q", addr, cluster.setName)
-	}
-
-	if result.IsMaster {
-		debugf("SYNC %s is a master.", addr)
-		if !server.info.Master {
-			// Made an incorrect assumption above, so fix stats.
-			stats.conn(-1, false)
-			stats.conn(+1, true)
-		}
-	} else if result.Secondary {
-		debugf("SYNC %s is a slave.", addr)
-	} else if cluster.direct {
-		logf("SYNC %s in unknown state. Pretending it's a slave due to direct connection.", addr)
-	} else {
-		logf("SYNC %s is neither a master nor a slave.", addr)
-		// Let stats track it as whatever was known before.
-		return nil, nil, errors.New(addr + " is not a master nor slave")
-	}
-
-	info = &mongoServerInfo{
-		Master:         result.IsMaster,
-		Mongos:         result.Msg == "isdbgrid",
-		Tags:           result.Tags,
-		SetName:        result.SetName,
-		MaxWireVersion: result.MaxWireVersion,
-	}
-
-	hosts = make([]string, 0, 1+len(result.Hosts)+len(result.Passives))
-	if result.Primary != "" {
-		// First in the list to speed up master discovery.
-		hosts = append(hosts, result.Primary)
-	}
-	hosts = append(hosts, result.Hosts...)
-	hosts = append(hosts, result.Passives...)
-
-	debugf("SYNC %s knows about the following peers: %#v", addr, hosts)
-	return info, hosts, nil
-}
-
-type syncKind bool
-
-const (
-	completeSync syncKind = true
-	partialSync  syncKind = false
-)
-
-func (cluster *mongoCluster) addServer(server *mongoServer, info *mongoServerInfo, syncKind syncKind) {
-	cluster.Lock()
-	current := cluster.servers.Search(server.ResolvedAddr)
-	if current == nil {
-		if syncKind == partialSync {
-			cluster.Unlock()
-			server.Close()
-			log("SYNC Discarding unknown server ", server.Addr, " due to partial sync.")
-			return
-		}
-		cluster.servers.Add(server)
-		if info.Master {
-			cluster.masters.Add(server)
-			log("SYNC Adding ", server.Addr, " to cluster as a master.")
-		} else {
-			log("SYNC Adding ", server.Addr, " to cluster as a slave.")
-		}
-	} else {
-		if server != current {
-			panic("addServer attempting to add duplicated server")
-		}
-		if server.Info().Master != info.Master {
-			if info.Master {
-				log("SYNC Server ", server.Addr, " is now a master.")
-				cluster.masters.Add(server)
-			} else {
-				log("SYNC Server ", server.Addr, " is now a slave.")
-				cluster.masters.Remove(server)
-			}
-		}
-	}
-	server.SetInfo(info)
-	debugf("SYNC Broadcasting availability of server %s", server.Addr)
-	cluster.serverSynced.Broadcast()
-	cluster.Unlock()
-}
-
-func (cluster *mongoCluster) getKnownAddrs() []string {
-	cluster.RLock()
-	max := len(cluster.userSeeds) + len(cluster.dynaSeeds) + cluster.servers.Len()
-	seen := make(map[string]bool, max)
-	known := make([]string, 0, max)
-
-	add := func(addr string) {
-		if _, found := seen[addr]; !found {
-			seen[addr] = true
-			known = append(known, addr)
-		}
-	}
-
-	for _, addr := range cluster.userSeeds {
-		add(addr)
-	}
-	for _, addr := range cluster.dynaSeeds {
-		add(addr)
-	}
-	for _, serv := range cluster.servers.Slice() {
-		add(serv.Addr)
-	}
-	cluster.RUnlock()
-
-	return known
-}
-
-// syncServers injects a value into the cluster.sync channel to force
-// an iteration of the syncServersLoop function.
-func (cluster *mongoCluster) syncServers() {
-	select {
-	case cluster.sync <- true:
-	default:
-	}
-}
-
-// How long to wait for a checkup of the cluster topology if nothing
-// else kicks a synchronization before that.
-const syncServersDelay = 30 * time.Second
-const syncShortDelay = 500 * time.Millisecond
-
-// syncServersLoop loops while the cluster is alive to keep its idea of
-// the server topology up-to-date. It must be called just once from
-// newCluster.  The loop iterates once syncServersDelay has passed, or
-// if somebody injects a value into the cluster.sync channel to force a
-// synchronization.  A loop iteration will contact all servers in
-// parallel, ask them about known peers and their own role within the
-// cluster, and then attempt to do the same with all the peers
-// retrieved.
-func (cluster *mongoCluster) syncServersLoop() {
-	for {
-		debugf("SYNC Cluster %p is starting a sync loop iteration.", cluster)
-
-		cluster.Lock()
-		if cluster.references == 0 {
-			cluster.Unlock()
-			break
-		}
-		cluster.references++ // Keep alive while syncing.
-		direct := cluster.direct
-		cluster.Unlock()
-
-		cluster.syncServersIteration(direct)
-
-		// We just synchronized, so consume any outstanding requests.
-		select {
-		case <-cluster.sync:
-		default:
-		}
-
-		cluster.Release()
-
-		// Hold off before allowing another sync. No point in
-		// burning CPU looking for down servers.
-		if !cluster.failFast {
-			time.Sleep(syncShortDelay)
-		}
-
-		cluster.Lock()
-		if cluster.references == 0 {
-			cluster.Unlock()
-			break
-		}
-		cluster.syncCount++
-		// Poke all waiters so they have a chance to timeout or
-		// restart syncing if they wish to.
-		cluster.serverSynced.Broadcast()
-		// Check if we have to restart immediately either way.
-		restart := !direct && cluster.masters.Empty() || cluster.servers.Empty()
-		cluster.Unlock()
-
-		if restart {
-			log("SYNC No masters found. Will synchronize again.")
-			time.Sleep(syncShortDelay)
-			continue
-		}
-
-		debugf("SYNC Cluster %p waiting for next requested or scheduled sync.", cluster)
-
-		// Hold off until somebody explicitly requests a synchronization
-		// or it's time to check for a cluster topology change again.
-		select {
-		case <-cluster.sync:
-		case <-time.After(syncServersDelay):
-		}
-	}
-	debugf("SYNC Cluster %p is stopping its sync loop.", cluster)
-}
-
-func (cluster *mongoCluster) server(addr string, tcpaddr *net.TCPAddr) *mongoServer {
-	cluster.RLock()
-	server := cluster.servers.Search(tcpaddr.String())
-	cluster.RUnlock()
-	if server != nil {
-		return server
-	}
-	return newServer(addr, tcpaddr, cluster.sync, cluster.dial)
-}
-
-func resolveAddr(addr string) (*net.TCPAddr, error) {
-	// Simple cases that do not need actual resolution. Works with IPv4 and v6.
-	if host, port, err := net.SplitHostPort(addr); err == nil {
-		if port, _ := strconv.Atoi(port); port > 0 {
-			zone := ""
-			if i := strings.LastIndex(host, "%"); i >= 0 {
-				zone = host[i+1:]
-				host = host[:i]
-			}
-			ip := net.ParseIP(host)
-			if ip != nil {
-				return &net.TCPAddr{IP: ip, Port: port, Zone: zone}, nil
-			}
-		}
-	}
-
-	// Attempt to resolve IPv4 and v6 concurrently.
-	addrChan := make(chan *net.TCPAddr, 2)
-	for _, network := range []string{"udp4", "udp6"} {
-		network := network
-		go func() {
-			// The unfortunate UDP dialing hack allows having a timeout on address resolution.
-			conn, err := net.DialTimeout(network, addr, 10*time.Second)
-			if err != nil {
-				addrChan <- nil
-			} else {
-				addrChan <- (*net.TCPAddr)(conn.RemoteAddr().(*net.UDPAddr))
-				conn.Close()
-			}
-		}()
-	}
-
-	// Wait for the result of IPv4 and v6 resolution. Use IPv4 if available.
-	tcpaddr := <-addrChan
-	if tcpaddr == nil || len(tcpaddr.IP) != 4 {
-		var timeout <-chan time.Time
-		if tcpaddr != nil {
-			// Don't wait too long if an IPv6 address is known.
-			timeout = time.After(50 * time.Millisecond)
-		}
-		select {
-		case <-timeout:
-		case tcpaddr2 := <-addrChan:
-			if tcpaddr == nil || tcpaddr2 != nil {
-				// It's an IPv4 address or the only known address. Use it.
-				tcpaddr = tcpaddr2
-			}
-		}
-	}
-
-	if tcpaddr == nil {
-		log("SYNC Failed to resolve server address: ", addr)
-		return nil, errors.New("failed to resolve server address: " + addr)
-	}
-	if tcpaddr.String() != addr {
-		debug("SYNC Address ", addr, " resolved as ", tcpaddr.String())
-	}
-	return tcpaddr, nil
-}
-
-type pendingAdd struct {
-	server *mongoServer
-	info   *mongoServerInfo
-}
-
-func (cluster *mongoCluster) syncServersIteration(direct bool) {
-	log("SYNC Starting full topology synchronization...")
-
-	var wg sync.WaitGroup
-	var m sync.Mutex
-	notYetAdded := make(map[string]pendingAdd)
-	addIfFound := make(map[string]bool)
-	seen := make(map[string]bool)
-	syncKind := partialSync
-
-	var spawnSync func(addr string, byMaster bool)
-	spawnSync = func(addr string, byMaster bool) {
-		wg.Add(1)
-		go func() {
-			defer wg.Done()
-
-			tcpaddr, err := resolveAddr(addr)
-			if err != nil {
-				log("SYNC Failed to start sync of ", addr, ": ", err.Error())
-				return
-			}
-			resolvedAddr := tcpaddr.String()
-
-			m.Lock()
-			if byMaster {
-				if pending, ok := notYetAdded[resolvedAddr]; ok {
-					delete(notYetAdded, resolvedAddr)
-					m.Unlock()
-					cluster.addServer(pending.server, pending.info, completeSync)
-					return
-				}
-				addIfFound[resolvedAddr] = true
-			}
-			if seen[resolvedAddr] {
-				m.Unlock()
-				return
-			}
-			seen[resolvedAddr] = true
-			m.Unlock()
-
-			server := cluster.server(addr, tcpaddr)
-			info, hosts, err := cluster.syncServer(server)
-			if err != nil {
-				cluster.removeServer(server)
-				return
-			}
-
-			m.Lock()
-			add := direct || info.Master || addIfFound[resolvedAddr]
-			if add {
-				syncKind = completeSync
-			} else {
-				notYetAdded[resolvedAddr] = pendingAdd{server, info}
-			}
-			m.Unlock()
-			if add {
-				cluster.addServer(server, info, completeSync)
-			}
-			if !direct {
-				for _, addr := range hosts {
-					spawnSync(addr, info.Master)
-				}
-			}
-		}()
-	}
-
-	knownAddrs := cluster.getKnownAddrs()
-	for _, addr := range knownAddrs {
-		spawnSync(addr, false)
-	}
-	wg.Wait()
-
-	if syncKind == completeSync {
-		logf("SYNC Synchronization was complete (got data from primary).")
-		for _, pending := range notYetAdded {
-			cluster.removeServer(pending.server)
-		}
-	} else {
-		logf("SYNC Synchronization was partial (cannot talk to primary).")
-		for _, pending := range notYetAdded {
-			cluster.addServer(pending.server, pending.info, partialSync)
-		}
-	}
-
-	cluster.Lock()
-	mastersLen := cluster.masters.Len()
-	logf("SYNC Synchronization completed: %d master(s) and %d slave(s) alive.", mastersLen, cluster.servers.Len()-mastersLen)
-
-	// Update dynamic seeds, but only if we have any good servers. Otherwise,
-	// leave them alone for better chances of a successful sync in the future.
-	if syncKind == completeSync {
-		dynaSeeds := make([]string, cluster.servers.Len())
-		for i, server := range cluster.servers.Slice() {
-			dynaSeeds[i] = server.Addr
-		}
-		cluster.dynaSeeds = dynaSeeds
-		debugf("SYNC New dynamic seeds: %#v\n", dynaSeeds)
-	}
-	cluster.Unlock()
-}
-
-// AcquireSocket returns a socket to a server in the cluster.  If slaveOk is
-// true, it will attempt to return a socket to a slave server.  If it is
-// false, the socket will necessarily be to a master server.
-func (cluster *mongoCluster) AcquireSocket(mode Mode, slaveOk bool, syncTimeout time.Duration, socketTimeout time.Duration, serverTags []bson.D, poolLimit int) (s *mongoSocket, err error) {
-	var started time.Time
-	var syncCount uint
-	warnedLimit := false
-	for {
-		cluster.RLock()
-		for {
-			mastersLen := cluster.masters.Len()
-			slavesLen := cluster.servers.Len() - mastersLen
-			debugf("Cluster has %d known masters and %d known slaves.", mastersLen, slavesLen)
-			if mastersLen > 0 && !(slaveOk && mode == Secondary) || slavesLen > 0 && slaveOk {
-				break
-			}
-			if mastersLen > 0 && mode == Secondary && cluster.masters.HasMongos() {
-				break
-			}
-			if started.IsZero() {
-				// Initialize after fast path above.
-				started = time.Now()
-				syncCount = cluster.syncCount
-			} else if syncTimeout != 0 && started.Before(time.Now().Add(-syncTimeout)) || cluster.failFast && cluster.syncCount != syncCount {
-				cluster.RUnlock()
-				return nil, errors.New("no reachable servers")
-			}
-			log("Waiting for servers to synchronize...")
-			cluster.syncServers()
-
-			// Remember: this will release and reacquire the lock.
-			cluster.serverSynced.Wait()
-		}
-
-		var server *mongoServer
-		if slaveOk {
-			server = cluster.servers.BestFit(mode, serverTags)
-		} else {
-			server = cluster.masters.BestFit(mode, nil)
-		}
-		cluster.RUnlock()
-
-		if server == nil {
-			// Must have failed the requested tags. Sleep to avoid spinning.
-			time.Sleep(1e8)
-			continue
-		}
-
-		s, abended, err := server.AcquireSocket(poolLimit, socketTimeout)
-		if err == errPoolLimit {
-			if !warnedLimit {
-				warnedLimit = true
-				log("WARNING: Per-server connection limit reached.")
-			}
-			time.Sleep(100 * time.Millisecond)
-			continue
-		}
-		if err != nil {
-			cluster.removeServer(server)
-			cluster.syncServers()
-			continue
-		}
-		if abended && !slaveOk {
-			var result isMasterResult
-			err := cluster.isMaster(s, &result)
-			if err != nil || !result.IsMaster {
-				logf("Cannot confirm server %s as master (%v)", server.Addr, err)
-				s.Release()
-				cluster.syncServers()
-				time.Sleep(100 * time.Millisecond)
-				continue
-			}
-		}
-		return s, nil
-	}
-	panic("unreached")
-}
-
-func (cluster *mongoCluster) CacheIndex(cacheKey string, exists bool) {
-	cluster.Lock()
-	if cluster.cachedIndex == nil {
-		cluster.cachedIndex = make(map[string]bool)
-	}
-	if exists {
-		cluster.cachedIndex[cacheKey] = true
-	} else {
-		delete(cluster.cachedIndex, cacheKey)
-	}
-	cluster.Unlock()
-}
-
-func (cluster *mongoCluster) HasCachedIndex(cacheKey string) (result bool) {
-	cluster.RLock()
-	if cluster.cachedIndex != nil {
-		result = cluster.cachedIndex[cacheKey]
-	}
-	cluster.RUnlock()
-	return
-}
-
-func (cluster *mongoCluster) ResetIndexCache() {
-	cluster.Lock()
-	cluster.cachedIndex = make(map[string]bool)
-	cluster.Unlock()
-}
diff --git a/vendor/gopkg.in/mgo.v2/doc.go b/vendor/gopkg.in/mgo.v2/doc.go
deleted file mode 100644
index 859fd9b..0000000
--- a/vendor/gopkg.in/mgo.v2/doc.go
+++ /dev/null
@@ -1,31 +0,0 @@
-// Package mgo offers a rich MongoDB driver for Go.
-//
-// Details about the mgo project (pronounced as "mango") are found
-// in its web page:
-//
-//     http://labix.org/mgo
-//
-// Usage of the driver revolves around the concept of sessions.  To
-// get started, obtain a session using the Dial function:
-//
-//     session, err := mgo.Dial(url)
-//
-// This will establish one or more connections with the cluster of
-// servers defined by the url parameter.  From then on, the cluster
-// may be queried with multiple consistency rules (see SetMode) and
-// documents retrieved with statements such as:
-//
-//     c := session.DB(database).C(collection)
-//     err := c.Find(query).One(&result)
-//
-// New sessions are typically created by calling session.Copy on the
-// initial session obtained at dial time. These new sessions will share
-// the same cluster information and connection pool, and may be easily
-// handed into other methods and functions for organizing logic.
-// Every session created must have its Close method called at the end
-// of its life time, so its resources may be put back in the pool or
-// collected, depending on the case.
-//
-// For more details, see the documentation for the types and methods.
-//
-package mgo
diff --git a/vendor/gopkg.in/mgo.v2/gridfs.go b/vendor/gopkg.in/mgo.v2/gridfs.go
deleted file mode 100644
index 4214720..0000000
--- a/vendor/gopkg.in/mgo.v2/gridfs.go
+++ /dev/null
@@ -1,761 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"crypto/md5"
-	"encoding/hex"
-	"errors"
-	"hash"
-	"io"
-	"os"
-	"sync"
-	"time"
-
-	"gopkg.in/mgo.v2/bson"
-)
-
-type GridFS struct {
-	Files  *Collection
-	Chunks *Collection
-}
-
-type gfsFileMode int
-
-const (
-	gfsClosed  gfsFileMode = 0
-	gfsReading gfsFileMode = 1
-	gfsWriting gfsFileMode = 2
-)
-
-type GridFile struct {
-	m    sync.Mutex
-	c    sync.Cond
-	gfs  *GridFS
-	mode gfsFileMode
-	err  error
-
-	chunk  int
-	offset int64
-
-	wpending int
-	wbuf     []byte
-	wsum     hash.Hash
-
-	rbuf   []byte
-	rcache *gfsCachedChunk
-
-	doc gfsFile
-}
-
-type gfsFile struct {
-	Id          interface{} "_id"
-	ChunkSize   int         "chunkSize"
-	UploadDate  time.Time   "uploadDate"
-	Length      int64       ",minsize"
-	MD5         string
-	Filename    string    ",omitempty"
-	ContentType string    "contentType,omitempty"
-	Metadata    *bson.Raw ",omitempty"
-}
-
-type gfsChunk struct {
-	Id      interface{} "_id"
-	FilesId interface{} "files_id"
-	N       int
-	Data    []byte
-}
-
-type gfsCachedChunk struct {
-	wait sync.Mutex
-	n    int
-	data []byte
-	err  error
-}
-
-func newGridFS(db *Database, prefix string) *GridFS {
-	return &GridFS{db.C(prefix + ".files"), db.C(prefix + ".chunks")}
-}
-
-func (gfs *GridFS) newFile() *GridFile {
-	file := &GridFile{gfs: gfs}
-	file.c.L = &file.m
-	//runtime.SetFinalizer(file, finalizeFile)
-	return file
-}
-
-func finalizeFile(file *GridFile) {
-	file.Close()
-}
-
-// Create creates a new file with the provided name in the GridFS.  If the file
-// name already exists, a new version will be inserted with an up-to-date
-// uploadDate that will cause it to be atomically visible to the Open and
-// OpenId methods.  If the file name is not important, an empty name may be
-// provided and the file Id used instead.
-//
-// It's important to Close files whether they are being written to
-// or read from, and to check the err result to ensure the operation
-// completed successfully.
-//
-// A simple example inserting a new file:
-//
-//     func check(err error) {
-//         if err != nil {
-//             panic(err.String())
-//         }
-//     }
-//     file, err := db.GridFS("fs").Create("myfile.txt")
-//     check(err)
-//     n, err := file.Write([]byte("Hello world!"))
-//     check(err)
-//     err = file.Close()
-//     check(err)
-//     fmt.Printf("%d bytes written\n", n)
-//
-// The io.Writer interface is implemented by *GridFile and may be used to
-// help on the file creation.  For example:
-//
-//     file, err := db.GridFS("fs").Create("myfile.txt")
-//     check(err)
-//     messages, err := os.Open("/var/log/messages")
-//     check(err)
-//     defer messages.Close()
-//     err = io.Copy(file, messages)
-//     check(err)
-//     err = file.Close()
-//     check(err)
-//
-func (gfs *GridFS) Create(name string) (file *GridFile, err error) {
-	file = gfs.newFile()
-	file.mode = gfsWriting
-	file.wsum = md5.New()
-	file.doc = gfsFile{Id: bson.NewObjectId(), ChunkSize: 255 * 1024, Filename: name}
-	return
-}
-
-// OpenId returns the file with the provided id, for reading.
-// If the file isn't found, err will be set to mgo.ErrNotFound.
-//
-// It's important to Close files whether they are being written to
-// or read from, and to check the err result to ensure the operation
-// completed successfully.
-//
-// The following example will print the first 8192 bytes from the file:
-//
-//     func check(err error) {
-//         if err != nil {
-//             panic(err.String())
-//         }
-//     }
-//     file, err := db.GridFS("fs").OpenId(objid)
-//     check(err)
-//     b := make([]byte, 8192)
-//     n, err := file.Read(b)
-//     check(err)
-//     fmt.Println(string(b))
-//     check(err)
-//     err = file.Close()
-//     check(err)
-//     fmt.Printf("%d bytes read\n", n)
-//
-// The io.Reader interface is implemented by *GridFile and may be used to
-// deal with it.  As an example, the following snippet will dump the whole
-// file into the standard output:
-//
-//     file, err := db.GridFS("fs").OpenId(objid)
-//     check(err)
-//     err = io.Copy(os.Stdout, file)
-//     check(err)
-//     err = file.Close()
-//     check(err)
-//
-func (gfs *GridFS) OpenId(id interface{}) (file *GridFile, err error) {
-	var doc gfsFile
-	err = gfs.Files.Find(bson.M{"_id": id}).One(&doc)
-	if err != nil {
-		return
-	}
-	file = gfs.newFile()
-	file.mode = gfsReading
-	file.doc = doc
-	return
-}
-
-// Open returns the most recently uploaded file with the provided
-// name, for reading. If the file isn't found, err will be set
-// to mgo.ErrNotFound.
-//
-// It's important to Close files whether they are being written to
-// or read from, and to check the err result to ensure the operation
-// completed successfully.
-//
-// The following example will print the first 8192 bytes from the file:
-//
-//     file, err := db.GridFS("fs").Open("myfile.txt")
-//     check(err)
-//     b := make([]byte, 8192)
-//     n, err := file.Read(b)
-//     check(err)
-//     fmt.Println(string(b))
-//     check(err)
-//     err = file.Close()
-//     check(err)
-//     fmt.Printf("%d bytes read\n", n)
-//
-// The io.Reader interface is implemented by *GridFile and may be used to
-// deal with it.  As an example, the following snippet will dump the whole
-// file into the standard output:
-//
-//     file, err := db.GridFS("fs").Open("myfile.txt")
-//     check(err)
-//     err = io.Copy(os.Stdout, file)
-//     check(err)
-//     err = file.Close()
-//     check(err)
-//
-func (gfs *GridFS) Open(name string) (file *GridFile, err error) {
-	var doc gfsFile
-	err = gfs.Files.Find(bson.M{"filename": name}).Sort("-uploadDate").One(&doc)
-	if err != nil {
-		return
-	}
-	file = gfs.newFile()
-	file.mode = gfsReading
-	file.doc = doc
-	return
-}
-
-// OpenNext opens the next file from iter for reading, sets *file to it,
-// and returns true on the success case. If no more documents are available
-// on iter or an error occurred, *file is set to nil and the result is false.
-// Errors will be available via iter.Err().
-//
-// The iter parameter must be an iterator on the GridFS files collection.
-// Using the GridFS.Find method is an easy way to obtain such an iterator,
-// but any iterator on the collection will work.
-//
-// If the provided *file is non-nil, OpenNext will close it before attempting
-// to iterate to the next element. This means that in a loop one only
-// has to worry about closing files when breaking out of the loop early
-// (break, return, or panic).
-//
-// For example:
-//
-//     gfs := db.GridFS("fs")
-//     query := gfs.Find(nil).Sort("filename")
-//     iter := query.Iter()
-//     var f *mgo.GridFile
-//     for gfs.OpenNext(iter, &f) {
-//         fmt.Printf("Filename: %s\n", f.Name())
-//     }
-//     if iter.Close() != nil {
-//         panic(iter.Close())
-//     }
-//
-func (gfs *GridFS) OpenNext(iter *Iter, file **GridFile) bool {
-	if *file != nil {
-		// Ignoring the error here shouldn't be a big deal
-		// as we're reading the file and the loop iteration
-		// for this file is finished.
-		_ = (*file).Close()
-	}
-	var doc gfsFile
-	if !iter.Next(&doc) {
-		*file = nil
-		return false
-	}
-	f := gfs.newFile()
-	f.mode = gfsReading
-	f.doc = doc
-	*file = f
-	return true
-}
-
-// Find runs query on GridFS's files collection and returns
-// the resulting Query.
-//
-// This logic:
-//
-//     gfs := db.GridFS("fs")
-//     iter := gfs.Find(nil).Iter()
-//
-// Is equivalent to:
-//
-//     files := db.C("fs" + ".files")
-//     iter := files.Find(nil).Iter()
-//
-func (gfs *GridFS) Find(query interface{}) *Query {
-	return gfs.Files.Find(query)
-}
-
-// RemoveId deletes the file with the provided id from the GridFS.
-func (gfs *GridFS) RemoveId(id interface{}) error {
-	err := gfs.Files.Remove(bson.M{"_id": id})
-	if err != nil {
-		return err
-	}
-	_, err = gfs.Chunks.RemoveAll(bson.D{{"files_id", id}})
-	return err
-}
-
-type gfsDocId struct {
-	Id interface{} "_id"
-}
-
-// Remove deletes all files with the provided name from the GridFS.
-func (gfs *GridFS) Remove(name string) (err error) {
-	iter := gfs.Files.Find(bson.M{"filename": name}).Select(bson.M{"_id": 1}).Iter()
-	var doc gfsDocId
-	for iter.Next(&doc) {
-		if e := gfs.RemoveId(doc.Id); e != nil {
-			err = e
-		}
-	}
-	if err == nil {
-		err = iter.Close()
-	}
-	return err
-}
-
-func (file *GridFile) assertMode(mode gfsFileMode) {
-	switch file.mode {
-	case mode:
-		return
-	case gfsWriting:
-		panic("GridFile is open for writing")
-	case gfsReading:
-		panic("GridFile is open for reading")
-	case gfsClosed:
-		panic("GridFile is closed")
-	default:
-		panic("internal error: missing GridFile mode")
-	}
-}
-
-// SetChunkSize sets size of saved chunks.  Once the file is written to, it
-// will be split in blocks of that size and each block saved into an
-// independent chunk document.  The default chunk size is 255kb.
-//
-// It is a runtime error to call this function once the file has started
-// being written to.
-func (file *GridFile) SetChunkSize(bytes int) {
-	file.assertMode(gfsWriting)
-	debugf("GridFile %p: setting chunk size to %d", file, bytes)
-	file.m.Lock()
-	file.doc.ChunkSize = bytes
-	file.m.Unlock()
-}
-
-// Id returns the current file Id.
-func (file *GridFile) Id() interface{} {
-	return file.doc.Id
-}
-
-// SetId changes the current file Id.
-//
-// It is a runtime error to call this function once the file has started
-// being written to, or when the file is not open for writing.
-func (file *GridFile) SetId(id interface{}) {
-	file.assertMode(gfsWriting)
-	file.m.Lock()
-	file.doc.Id = id
-	file.m.Unlock()
-}
-
-// Name returns the optional file name.  An empty string will be returned
-// in case it is unset.
-func (file *GridFile) Name() string {
-	return file.doc.Filename
-}
-
-// SetName changes the optional file name.  An empty string may be used to
-// unset it.
-//
-// It is a runtime error to call this function when the file is not open
-// for writing.
-func (file *GridFile) SetName(name string) {
-	file.assertMode(gfsWriting)
-	file.m.Lock()
-	file.doc.Filename = name
-	file.m.Unlock()
-}
-
-// ContentType returns the optional file content type.  An empty string will be
-// returned in case it is unset.
-func (file *GridFile) ContentType() string {
-	return file.doc.ContentType
-}
-
-// ContentType changes the optional file content type.  An empty string may be
-// used to unset it.
-//
-// It is a runtime error to call this function when the file is not open
-// for writing.
-func (file *GridFile) SetContentType(ctype string) {
-	file.assertMode(gfsWriting)
-	file.m.Lock()
-	file.doc.ContentType = ctype
-	file.m.Unlock()
-}
-
-// GetMeta unmarshals the optional "metadata" field associated with the
-// file into the result parameter. The meaning of keys under that field
-// is user-defined. For example:
-//
-//     result := struct{ INode int }{}
-//     err = file.GetMeta(&result)
-//     if err != nil {
-//         panic(err.String())
-//     }
-//     fmt.Printf("inode: %d\n", result.INode)
-//
-func (file *GridFile) GetMeta(result interface{}) (err error) {
-	file.m.Lock()
-	if file.doc.Metadata != nil {
-		err = bson.Unmarshal(file.doc.Metadata.Data, result)
-	}
-	file.m.Unlock()
-	return
-}
-
-// SetMeta changes the optional "metadata" field associated with the
-// file. The meaning of keys under that field is user-defined.
-// For example:
-//
-//     file.SetMeta(bson.M{"inode": inode})
-//
-// It is a runtime error to call this function when the file is not open
-// for writing.
-func (file *GridFile) SetMeta(metadata interface{}) {
-	file.assertMode(gfsWriting)
-	data, err := bson.Marshal(metadata)
-	file.m.Lock()
-	if err != nil && file.err == nil {
-		file.err = err
-	} else {
-		file.doc.Metadata = &bson.Raw{Data: data}
-	}
-	file.m.Unlock()
-}
-
-// Size returns the file size in bytes.
-func (file *GridFile) Size() (bytes int64) {
-	file.m.Lock()
-	bytes = file.doc.Length
-	file.m.Unlock()
-	return
-}
-
-// MD5 returns the file MD5 as a hex-encoded string.
-func (file *GridFile) MD5() (md5 string) {
-	return file.doc.MD5
-}
-
-// UploadDate returns the file upload time.
-func (file *GridFile) UploadDate() time.Time {
-	return file.doc.UploadDate
-}
-
-// SetUploadDate changes the file upload time.
-//
-// It is a runtime error to call this function when the file is not open
-// for writing.
-func (file *GridFile) SetUploadDate(t time.Time) {
-	file.assertMode(gfsWriting)
-	file.m.Lock()
-	file.doc.UploadDate = t
-	file.m.Unlock()
-}
-
-// Close flushes any pending changes in case the file is being written
-// to, waits for any background operations to finish, and closes the file.
-//
-// It's important to Close files whether they are being written to
-// or read from, and to check the err result to ensure the operation
-// completed successfully.
-func (file *GridFile) Close() (err error) {
-	file.m.Lock()
-	defer file.m.Unlock()
-	if file.mode == gfsWriting {
-		if len(file.wbuf) > 0 && file.err == nil {
-			file.insertChunk(file.wbuf)
-			file.wbuf = file.wbuf[0:0]
-		}
-		file.completeWrite()
-	} else if file.mode == gfsReading && file.rcache != nil {
-		file.rcache.wait.Lock()
-		file.rcache = nil
-	}
-	file.mode = gfsClosed
-	debugf("GridFile %p: closed", file)
-	return file.err
-}
-
-func (file *GridFile) completeWrite() {
-	for file.wpending > 0 {
-		debugf("GridFile %p: waiting for %d pending chunks to complete file write", file, file.wpending)
-		file.c.Wait()
-	}
-	if file.err == nil {
-		hexsum := hex.EncodeToString(file.wsum.Sum(nil))
-		if file.doc.UploadDate.IsZero() {
-			file.doc.UploadDate = bson.Now()
-		}
-		file.doc.MD5 = hexsum
-		file.err = file.gfs.Files.Insert(file.doc)
-	}
-	if file.err != nil {
-		file.gfs.Chunks.RemoveAll(bson.D{{"files_id", file.doc.Id}})
-	}
-	if file.err == nil {
-		index := Index{
-			Key:    []string{"files_id", "n"},
-			Unique: true,
-		}
-		file.err = file.gfs.Chunks.EnsureIndex(index)
-	}
-}
-
-// Abort cancels an in-progress write, preventing the file from being
-// automically created and ensuring previously written chunks are
-// removed when the file is closed.
-//
-// It is a runtime error to call Abort when the file was not opened
-// for writing.
-func (file *GridFile) Abort() {
-	if file.mode != gfsWriting {
-		panic("file.Abort must be called on file opened for writing")
-	}
-	file.err = errors.New("write aborted")
-}
-
-// Write writes the provided data to the file and returns the
-// number of bytes written and an error in case something
-// wrong happened.
-//
-// The file will internally cache the data so that all but the last
-// chunk sent to the database have the size defined by SetChunkSize.
-// This also means that errors may be deferred until a future call
-// to Write or Close.
-//
-// The parameters and behavior of this function turn the file
-// into an io.Writer.
-func (file *GridFile) Write(data []byte) (n int, err error) {
-	file.assertMode(gfsWriting)
-	file.m.Lock()
-	debugf("GridFile %p: writing %d bytes", file, len(data))
-	defer file.m.Unlock()
-
-	if file.err != nil {
-		return 0, file.err
-	}
-
-	n = len(data)
-	file.doc.Length += int64(n)
-	chunkSize := file.doc.ChunkSize
-
-	if len(file.wbuf)+len(data) < chunkSize {
-		file.wbuf = append(file.wbuf, data...)
-		return
-	}
-
-	// First, flush file.wbuf complementing with data.
-	if len(file.wbuf) > 0 {
-		missing := chunkSize - len(file.wbuf)
-		if missing > len(data) {
-			missing = len(data)
-		}
-		file.wbuf = append(file.wbuf, data[:missing]...)
-		data = data[missing:]
-		file.insertChunk(file.wbuf)
-		file.wbuf = file.wbuf[0:0]
-	}
-
-	// Then, flush all chunks from data without copying.
-	for len(data) > chunkSize {
-		size := chunkSize
-		if size > len(data) {
-			size = len(data)
-		}
-		file.insertChunk(data[:size])
-		data = data[size:]
-	}
-
-	// And append the rest for a future call.
-	file.wbuf = append(file.wbuf, data...)
-
-	return n, file.err
-}
-
-func (file *GridFile) insertChunk(data []byte) {
-	n := file.chunk
-	file.chunk++
-	debugf("GridFile %p: adding to checksum: %q", file, string(data))
-	file.wsum.Write(data)
-
-	for file.doc.ChunkSize*file.wpending >= 1024*1024 {
-		// Hold on.. we got a MB pending.
-		file.c.Wait()
-		if file.err != nil {
-			return
-		}
-	}
-
-	file.wpending++
-
-	debugf("GridFile %p: inserting chunk %d with %d bytes", file, n, len(data))
-
-	// We may not own the memory of data, so rather than
-	// simply copying it, we'll marshal the document ahead of time.
-	data, err := bson.Marshal(gfsChunk{bson.NewObjectId(), file.doc.Id, n, data})
-	if err != nil {
-		file.err = err
-		return
-	}
-
-	go func() {
-		err := file.gfs.Chunks.Insert(bson.Raw{Data: data})
-		file.m.Lock()
-		file.wpending--
-		if err != nil && file.err == nil {
-			file.err = err
-		}
-		file.c.Broadcast()
-		file.m.Unlock()
-	}()
-}
-
-// Seek sets the offset for the next Read or Write on file to
-// offset, interpreted according to whence: 0 means relative to
-// the origin of the file, 1 means relative to the current offset,
-// and 2 means relative to the end. It returns the new offset and
-// an error, if any.
-func (file *GridFile) Seek(offset int64, whence int) (pos int64, err error) {
-	file.m.Lock()
-	debugf("GridFile %p: seeking for %s (whence=%d)", file, offset, whence)
-	defer file.m.Unlock()
-	switch whence {
-	case os.SEEK_SET:
-	case os.SEEK_CUR:
-		offset += file.offset
-	case os.SEEK_END:
-		offset += file.doc.Length
-	default:
-		panic("unsupported whence value")
-	}
-	if offset > file.doc.Length {
-		return file.offset, errors.New("seek past end of file")
-	}
-	if offset == file.doc.Length {
-		// If we're seeking to the end of the file,
-		// no need to read anything. This enables
-		// a client to find the size of the file using only the
-		// io.ReadSeeker interface with low overhead.
-		file.offset = offset
-		return file.offset, nil
-	}
-	chunk := int(offset / int64(file.doc.ChunkSize))
-	if chunk+1 == file.chunk && offset >= file.offset {
-		file.rbuf = file.rbuf[int(offset-file.offset):]
-		file.offset = offset
-		return file.offset, nil
-	}
-	file.offset = offset
-	file.chunk = chunk
-	file.rbuf = nil
-	file.rbuf, err = file.getChunk()
-	if err == nil {
-		file.rbuf = file.rbuf[int(file.offset-int64(chunk)*int64(file.doc.ChunkSize)):]
-	}
-	return file.offset, err
-}
-
-// Read reads into b the next available data from the file and
-// returns the number of bytes written and an error in case
-// something wrong happened.  At the end of the file, n will
-// be zero and err will be set to io.EOF.
-//
-// The parameters and behavior of this function turn the file
-// into an io.Reader.
-func (file *GridFile) Read(b []byte) (n int, err error) {
-	file.assertMode(gfsReading)
-	file.m.Lock()
-	debugf("GridFile %p: reading at offset %d into buffer of length %d", file, file.offset, len(b))
-	defer file.m.Unlock()
-	if file.offset == file.doc.Length {
-		return 0, io.EOF
-	}
-	for err == nil {
-		i := copy(b, file.rbuf)
-		n += i
-		file.offset += int64(i)
-		file.rbuf = file.rbuf[i:]
-		if i == len(b) || file.offset == file.doc.Length {
-			break
-		}
-		b = b[i:]
-		file.rbuf, err = file.getChunk()
-	}
-	return n, err
-}
-
-func (file *GridFile) getChunk() (data []byte, err error) {
-	cache := file.rcache
-	file.rcache = nil
-	if cache != nil && cache.n == file.chunk {
-		debugf("GridFile %p: Getting chunk %d from cache", file, file.chunk)
-		cache.wait.Lock()
-		data, err = cache.data, cache.err
-	} else {
-		debugf("GridFile %p: Fetching chunk %d", file, file.chunk)
-		var doc gfsChunk
-		err = file.gfs.Chunks.Find(bson.D{{"files_id", file.doc.Id}, {"n", file.chunk}}).One(&doc)
-		data = doc.Data
-	}
-	file.chunk++
-	if int64(file.chunk)*int64(file.doc.ChunkSize) < file.doc.Length {
-		// Read the next one in background.
-		cache = &gfsCachedChunk{n: file.chunk}
-		cache.wait.Lock()
-		debugf("GridFile %p: Scheduling chunk %d for background caching", file, file.chunk)
-		// Clone the session to avoid having it closed in between.
-		chunks := file.gfs.Chunks
-		session := chunks.Database.Session.Clone()
-		go func(id interface{}, n int) {
-			defer session.Close()
-			chunks = chunks.With(session)
-			var doc gfsChunk
-			cache.err = chunks.Find(bson.D{{"files_id", id}, {"n", n}}).One(&doc)
-			cache.data = doc.Data
-			cache.wait.Unlock()
-		}(file.doc.Id, file.chunk)
-		file.rcache = cache
-	}
-	debugf("Returning err: %#v", err)
-	return
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/LICENSE b/vendor/gopkg.in/mgo.v2/internal/json/LICENSE
deleted file mode 100644
index 7448756..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/LICENSE
+++ /dev/null
@@ -1,27 +0,0 @@
-Copyright (c) 2012 The Go Authors. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-   * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-   * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-   * Neither the name of Google Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/decode.go b/vendor/gopkg.in/mgo.v2/internal/json/decode.go
deleted file mode 100644
index ce7c7d2..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/decode.go
+++ /dev/null
@@ -1,1685 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Represents JSON data structure using native Go types: booleans, floats,
-// strings, arrays, and maps.
-
-package json
-
-import (
-	"bytes"
-	"encoding"
-	"encoding/base64"
-	"errors"
-	"fmt"
-	"reflect"
-	"runtime"
-	"strconv"
-	"unicode"
-	"unicode/utf16"
-	"unicode/utf8"
-)
-
-// Unmarshal parses the JSON-encoded data and stores the result
-// in the value pointed to by v.
-//
-// Unmarshal uses the inverse of the encodings that
-// Marshal uses, allocating maps, slices, and pointers as necessary,
-// with the following additional rules:
-//
-// To unmarshal JSON into a pointer, Unmarshal first handles the case of
-// the JSON being the JSON literal null. In that case, Unmarshal sets
-// the pointer to nil. Otherwise, Unmarshal unmarshals the JSON into
-// the value pointed at by the pointer. If the pointer is nil, Unmarshal
-// allocates a new value for it to point to.
-//
-// To unmarshal JSON into a struct, Unmarshal matches incoming object
-// keys to the keys used by Marshal (either the struct field name or its tag),
-// preferring an exact match but also accepting a case-insensitive match.
-// Unmarshal will only set exported fields of the struct.
-//
-// To unmarshal JSON into an interface value,
-// Unmarshal stores one of these in the interface value:
-//
-//	bool, for JSON booleans
-//	float64, for JSON numbers
-//	string, for JSON strings
-//	[]interface{}, for JSON arrays
-//	map[string]interface{}, for JSON objects
-//	nil for JSON null
-//
-// To unmarshal a JSON array into a slice, Unmarshal resets the slice length
-// to zero and then appends each element to the slice.
-// As a special case, to unmarshal an empty JSON array into a slice,
-// Unmarshal replaces the slice with a new empty slice.
-//
-// To unmarshal a JSON array into a Go array, Unmarshal decodes
-// JSON array elements into corresponding Go array elements.
-// If the Go array is smaller than the JSON array,
-// the additional JSON array elements are discarded.
-// If the JSON array is smaller than the Go array,
-// the additional Go array elements are set to zero values.
-//
-// To unmarshal a JSON object into a map, Unmarshal first establishes a map to
-// use, If the map is nil, Unmarshal allocates a new map. Otherwise Unmarshal
-// reuses the existing map, keeping existing entries. Unmarshal then stores key-
-// value pairs from the JSON object into the map.  The map's key type must
-// either be a string or implement encoding.TextUnmarshaler.
-//
-// If a JSON value is not appropriate for a given target type,
-// or if a JSON number overflows the target type, Unmarshal
-// skips that field and completes the unmarshaling as best it can.
-// If no more serious errors are encountered, Unmarshal returns
-// an UnmarshalTypeError describing the earliest such error.
-//
-// The JSON null value unmarshals into an interface, map, pointer, or slice
-// by setting that Go value to nil. Because null is often used in JSON to mean
-// ``not present,'' unmarshaling a JSON null into any other Go type has no effect
-// on the value and produces no error.
-//
-// When unmarshaling quoted strings, invalid UTF-8 or
-// invalid UTF-16 surrogate pairs are not treated as an error.
-// Instead, they are replaced by the Unicode replacement
-// character U+FFFD.
-//
-func Unmarshal(data []byte, v interface{}) error {
-	// Check for well-formedness.
-	// Avoids filling out half a data structure
-	// before discovering a JSON syntax error.
-	var d decodeState
-	err := checkValid(data, &d.scan)
-	if err != nil {
-		return err
-	}
-
-	d.init(data)
-	return d.unmarshal(v)
-}
-
-// Unmarshaler is the interface implemented by types
-// that can unmarshal a JSON description of themselves.
-// The input can be assumed to be a valid encoding of
-// a JSON value. UnmarshalJSON must copy the JSON data
-// if it wishes to retain the data after returning.
-type Unmarshaler interface {
-	UnmarshalJSON([]byte) error
-}
-
-// An UnmarshalTypeError describes a JSON value that was
-// not appropriate for a value of a specific Go type.
-type UnmarshalTypeError struct {
-	Value  string       // description of JSON value - "bool", "array", "number -5"
-	Type   reflect.Type // type of Go value it could not be assigned to
-	Offset int64        // error occurred after reading Offset bytes
-}
-
-func (e *UnmarshalTypeError) Error() string {
-	return "json: cannot unmarshal " + e.Value + " into Go value of type " + e.Type.String()
-}
-
-// An UnmarshalFieldError describes a JSON object key that
-// led to an unexported (and therefore unwritable) struct field.
-// (No longer used; kept for compatibility.)
-type UnmarshalFieldError struct {
-	Key   string
-	Type  reflect.Type
-	Field reflect.StructField
-}
-
-func (e *UnmarshalFieldError) Error() string {
-	return "json: cannot unmarshal object key " + strconv.Quote(e.Key) + " into unexported field " + e.Field.Name + " of type " + e.Type.String()
-}
-
-// An InvalidUnmarshalError describes an invalid argument passed to Unmarshal.
-// (The argument to Unmarshal must be a non-nil pointer.)
-type InvalidUnmarshalError struct {
-	Type reflect.Type
-}
-
-func (e *InvalidUnmarshalError) Error() string {
-	if e.Type == nil {
-		return "json: Unmarshal(nil)"
-	}
-
-	if e.Type.Kind() != reflect.Ptr {
-		return "json: Unmarshal(non-pointer " + e.Type.String() + ")"
-	}
-	return "json: Unmarshal(nil " + e.Type.String() + ")"
-}
-
-func (d *decodeState) unmarshal(v interface{}) (err error) {
-	defer func() {
-		if r := recover(); r != nil {
-			if _, ok := r.(runtime.Error); ok {
-				panic(r)
-			}
-			err = r.(error)
-		}
-	}()
-
-	rv := reflect.ValueOf(v)
-	if rv.Kind() != reflect.Ptr || rv.IsNil() {
-		return &InvalidUnmarshalError{reflect.TypeOf(v)}
-	}
-
-	d.scan.reset()
-	// We decode rv not rv.Elem because the Unmarshaler interface
-	// test must be applied at the top level of the value.
-	d.value(rv)
-	return d.savedError
-}
-
-// A Number represents a JSON number literal.
-type Number string
-
-// String returns the literal text of the number.
-func (n Number) String() string { return string(n) }
-
-// Float64 returns the number as a float64.
-func (n Number) Float64() (float64, error) {
-	return strconv.ParseFloat(string(n), 64)
-}
-
-// Int64 returns the number as an int64.
-func (n Number) Int64() (int64, error) {
-	return strconv.ParseInt(string(n), 10, 64)
-}
-
-// isValidNumber reports whether s is a valid JSON number literal.
-func isValidNumber(s string) bool {
-	// This function implements the JSON numbers grammar.
-	// See https://tools.ietf.org/html/rfc7159#section-6
-	// and http://json.org/number.gif
-
-	if s == "" {
-		return false
-	}
-
-	// Optional -
-	if s[0] == '-' {
-		s = s[1:]
-		if s == "" {
-			return false
-		}
-	}
-
-	// Digits
-	switch {
-	default:
-		return false
-
-	case s[0] == '0':
-		s = s[1:]
-
-	case '1' <= s[0] && s[0] <= '9':
-		s = s[1:]
-		for len(s) > 0 && '0' <= s[0] && s[0] <= '9' {
-			s = s[1:]
-		}
-	}
-
-	// . followed by 1 or more digits.
-	if len(s) >= 2 && s[0] == '.' && '0' <= s[1] && s[1] <= '9' {
-		s = s[2:]
-		for len(s) > 0 && '0' <= s[0] && s[0] <= '9' {
-			s = s[1:]
-		}
-	}
-
-	// e or E followed by an optional - or + and
-	// 1 or more digits.
-	if len(s) >= 2 && (s[0] == 'e' || s[0] == 'E') {
-		s = s[1:]
-		if s[0] == '+' || s[0] == '-' {
-			s = s[1:]
-			if s == "" {
-				return false
-			}
-		}
-		for len(s) > 0 && '0' <= s[0] && s[0] <= '9' {
-			s = s[1:]
-		}
-	}
-
-	// Make sure we are at the end.
-	return s == ""
-}
-
-// decodeState represents the state while decoding a JSON value.
-type decodeState struct {
-	data       []byte
-	off        int // read offset in data
-	scan       scanner
-	nextscan   scanner // for calls to nextValue
-	savedError error
-	useNumber  bool
-	ext        Extension
-}
-
-// errPhase is used for errors that should not happen unless
-// there is a bug in the JSON decoder or something is editing
-// the data slice while the decoder executes.
-var errPhase = errors.New("JSON decoder out of sync - data changing underfoot?")
-
-func (d *decodeState) init(data []byte) *decodeState {
-	d.data = data
-	d.off = 0
-	d.savedError = nil
-	return d
-}
-
-// error aborts the decoding by panicking with err.
-func (d *decodeState) error(err error) {
-	panic(err)
-}
-
-// saveError saves the first err it is called with,
-// for reporting at the end of the unmarshal.
-func (d *decodeState) saveError(err error) {
-	if d.savedError == nil {
-		d.savedError = err
-	}
-}
-
-// next cuts off and returns the next full JSON value in d.data[d.off:].
-// The next value is known to be an object or array, not a literal.
-func (d *decodeState) next() []byte {
-	c := d.data[d.off]
-	item, rest, err := nextValue(d.data[d.off:], &d.nextscan)
-	if err != nil {
-		d.error(err)
-	}
-	d.off = len(d.data) - len(rest)
-
-	// Our scanner has seen the opening brace/bracket
-	// and thinks we're still in the middle of the object.
-	// invent a closing brace/bracket to get it out.
-	if c == '{' {
-		d.scan.step(&d.scan, '}')
-	} else if c == '[' {
-		d.scan.step(&d.scan, ']')
-	} else {
-		// Was inside a function name. Get out of it.
-		d.scan.step(&d.scan, '(')
-		d.scan.step(&d.scan, ')')
-	}
-
-	return item
-}
-
-// scanWhile processes bytes in d.data[d.off:] until it
-// receives a scan code not equal to op.
-// It updates d.off and returns the new scan code.
-func (d *decodeState) scanWhile(op int) int {
-	var newOp int
-	for {
-		if d.off >= len(d.data) {
-			newOp = d.scan.eof()
-			d.off = len(d.data) + 1 // mark processed EOF with len+1
-		} else {
-			c := d.data[d.off]
-			d.off++
-			newOp = d.scan.step(&d.scan, c)
-		}
-		if newOp != op {
-			break
-		}
-	}
-	return newOp
-}
-
-// value decodes a JSON value from d.data[d.off:] into the value.
-// it updates d.off to point past the decoded value.
-func (d *decodeState) value(v reflect.Value) {
-	if !v.IsValid() {
-		_, rest, err := nextValue(d.data[d.off:], &d.nextscan)
-		if err != nil {
-			d.error(err)
-		}
-		d.off = len(d.data) - len(rest)
-
-		// d.scan thinks we're still at the beginning of the item.
-		// Feed in an empty string - the shortest, simplest value -
-		// so that it knows we got to the end of the value.
-		if d.scan.redo {
-			// rewind.
-			d.scan.redo = false
-			d.scan.step = stateBeginValue
-		}
-		d.scan.step(&d.scan, '"')
-		d.scan.step(&d.scan, '"')
-
-		n := len(d.scan.parseState)
-		if n > 0 && d.scan.parseState[n-1] == parseObjectKey {
-			// d.scan thinks we just read an object key; finish the object
-			d.scan.step(&d.scan, ':')
-			d.scan.step(&d.scan, '"')
-			d.scan.step(&d.scan, '"')
-			d.scan.step(&d.scan, '}')
-		}
-
-		return
-	}
-
-	switch op := d.scanWhile(scanSkipSpace); op {
-	default:
-		d.error(errPhase)
-
-	case scanBeginArray:
-		d.array(v)
-
-	case scanBeginObject:
-		d.object(v)
-
-	case scanBeginLiteral:
-		d.literal(v)
-
-	case scanBeginName:
-		d.name(v)
-	}
-}
-
-type unquotedValue struct{}
-
-// valueQuoted is like value but decodes a
-// quoted string literal or literal null into an interface value.
-// If it finds anything other than a quoted string literal or null,
-// valueQuoted returns unquotedValue{}.
-func (d *decodeState) valueQuoted() interface{} {
-	switch op := d.scanWhile(scanSkipSpace); op {
-	default:
-		d.error(errPhase)
-
-	case scanBeginArray:
-		d.array(reflect.Value{})
-
-	case scanBeginObject:
-		d.object(reflect.Value{})
-
-	case scanBeginName:
-		switch v := d.nameInterface().(type) {
-		case nil, string:
-			return v
-		}
-
-	case scanBeginLiteral:
-		switch v := d.literalInterface().(type) {
-		case nil, string:
-			return v
-		}
-	}
-	return unquotedValue{}
-}
-
-// indirect walks down v allocating pointers as needed,
-// until it gets to a non-pointer.
-// if it encounters an Unmarshaler, indirect stops and returns that.
-// if decodingNull is true, indirect stops at the last pointer so it can be set to nil.
-func (d *decodeState) indirect(v reflect.Value, decodingNull bool) (Unmarshaler, encoding.TextUnmarshaler, reflect.Value) {
-	// If v is a named type and is addressable,
-	// start with its address, so that if the type has pointer methods,
-	// we find them.
-	if v.Kind() != reflect.Ptr && v.Type().Name() != "" && v.CanAddr() {
-		v = v.Addr()
-	}
-	for {
-		// Load value from interface, but only if the result will be
-		// usefully addressable.
-		if v.Kind() == reflect.Interface && !v.IsNil() {
-			e := v.Elem()
-			if e.Kind() == reflect.Ptr && !e.IsNil() && (!decodingNull || e.Elem().Kind() == reflect.Ptr) {
-				v = e
-				continue
-			}
-		}
-
-		if v.Kind() != reflect.Ptr {
-			break
-		}
-
-		if v.Elem().Kind() != reflect.Ptr && decodingNull && v.CanSet() {
-			break
-		}
-		if v.IsNil() {
-			v.Set(reflect.New(v.Type().Elem()))
-		}
-		if v.Type().NumMethod() > 0 {
-			if u, ok := v.Interface().(Unmarshaler); ok {
-				return u, nil, v
-			}
-			if u, ok := v.Interface().(encoding.TextUnmarshaler); ok {
-				return nil, u, v
-			}
-		}
-		v = v.Elem()
-	}
-	return nil, nil, v
-}
-
-// array consumes an array from d.data[d.off-1:], decoding into the value v.
-// the first byte of the array ('[') has been read already.
-func (d *decodeState) array(v reflect.Value) {
-	// Check for unmarshaler.
-	u, ut, pv := d.indirect(v, false)
-	if u != nil {
-		d.off--
-		err := u.UnmarshalJSON(d.next())
-		if err != nil {
-			d.error(err)
-		}
-		return
-	}
-	if ut != nil {
-		d.saveError(&UnmarshalTypeError{"array", v.Type(), int64(d.off)})
-		d.off--
-		d.next()
-		return
-	}
-
-	v = pv
-
-	// Check type of target.
-	switch v.Kind() {
-	case reflect.Interface:
-		if v.NumMethod() == 0 {
-			// Decoding into nil interface?  Switch to non-reflect code.
-			v.Set(reflect.ValueOf(d.arrayInterface()))
-			return
-		}
-		// Otherwise it's invalid.
-		fallthrough
-	default:
-		d.saveError(&UnmarshalTypeError{"array", v.Type(), int64(d.off)})
-		d.off--
-		d.next()
-		return
-	case reflect.Array:
-	case reflect.Slice:
-		break
-	}
-
-	i := 0
-	for {
-		// Look ahead for ] - can only happen on first iteration.
-		op := d.scanWhile(scanSkipSpace)
-		if op == scanEndArray {
-			break
-		}
-
-		// Back up so d.value can have the byte we just read.
-		d.off--
-		d.scan.undo(op)
-
-		// Get element of array, growing if necessary.
-		if v.Kind() == reflect.Slice {
-			// Grow slice if necessary
-			if i >= v.Cap() {
-				newcap := v.Cap() + v.Cap()/2
-				if newcap < 4 {
-					newcap = 4
-				}
-				newv := reflect.MakeSlice(v.Type(), v.Len(), newcap)
-				reflect.Copy(newv, v)
-				v.Set(newv)
-			}
-			if i >= v.Len() {
-				v.SetLen(i + 1)
-			}
-		}
-
-		if i < v.Len() {
-			// Decode into element.
-			d.value(v.Index(i))
-		} else {
-			// Ran out of fixed array: skip.
-			d.value(reflect.Value{})
-		}
-		i++
-
-		// Next token must be , or ].
-		op = d.scanWhile(scanSkipSpace)
-		if op == scanEndArray {
-			break
-		}
-		if op != scanArrayValue {
-			d.error(errPhase)
-		}
-	}
-
-	if i < v.Len() {
-		if v.Kind() == reflect.Array {
-			// Array. Zero the rest.
-			z := reflect.Zero(v.Type().Elem())
-			for ; i < v.Len(); i++ {
-				v.Index(i).Set(z)
-			}
-		} else {
-			v.SetLen(i)
-		}
-	}
-	if i == 0 && v.Kind() == reflect.Slice {
-		v.Set(reflect.MakeSlice(v.Type(), 0, 0))
-	}
-}
-
-var nullLiteral = []byte("null")
-var textUnmarshalerType = reflect.TypeOf(new(encoding.TextUnmarshaler)).Elem()
-
-// object consumes an object from d.data[d.off-1:], decoding into the value v.
-// the first byte ('{') of the object has been read already.
-func (d *decodeState) object(v reflect.Value) {
-	// Check for unmarshaler.
-	u, ut, pv := d.indirect(v, false)
-	if d.storeKeyed(pv) {
-		return
-	}
-	if u != nil {
-		d.off--
-		err := u.UnmarshalJSON(d.next())
-		if err != nil {
-			d.error(err)
-		}
-		return
-	}
-	if ut != nil {
-		d.saveError(&UnmarshalTypeError{"object", v.Type(), int64(d.off)})
-		d.off--
-		d.next() // skip over { } in input
-		return
-	}
-	v = pv
-
-	// Decoding into nil interface?  Switch to non-reflect code.
-	if v.Kind() == reflect.Interface && v.NumMethod() == 0 {
-		v.Set(reflect.ValueOf(d.objectInterface()))
-		return
-	}
-
-	// Check type of target:
-	//   struct or
-	//   map[string]T or map[encoding.TextUnmarshaler]T
-	switch v.Kind() {
-	case reflect.Map:
-		// Map key must either have string kind or be an encoding.TextUnmarshaler.
-		t := v.Type()
-		if t.Key().Kind() != reflect.String &&
-			!reflect.PtrTo(t.Key()).Implements(textUnmarshalerType) {
-			d.saveError(&UnmarshalTypeError{"object", v.Type(), int64(d.off)})
-			d.off--
-			d.next() // skip over { } in input
-			return
-		}
-		if v.IsNil() {
-			v.Set(reflect.MakeMap(t))
-		}
-	case reflect.Struct:
-
-	default:
-		d.saveError(&UnmarshalTypeError{"object", v.Type(), int64(d.off)})
-		d.off--
-		d.next() // skip over { } in input
-		return
-	}
-
-	var mapElem reflect.Value
-
-	empty := true
-	for {
-		// Read opening " of string key or closing }.
-		op := d.scanWhile(scanSkipSpace)
-		if op == scanEndObject {
-			if !empty && !d.ext.trailingCommas {
-				d.syntaxError("beginning of object key string")
-			}
-			break
-		}
-		empty = false
-		if op == scanBeginName {
-			if !d.ext.unquotedKeys {
-				d.syntaxError("beginning of object key string")
-			}
-		} else if op != scanBeginLiteral {
-			d.error(errPhase)
-		}
-		unquotedKey := op == scanBeginName
-
-		// Read key.
-		start := d.off - 1
-		op = d.scanWhile(scanContinue)
-		item := d.data[start : d.off-1]
-		var key []byte
-		if unquotedKey {
-			key = item
-			// TODO Fix code below to quote item when necessary.
-		} else {
-			var ok bool
-			key, ok = unquoteBytes(item)
-			if !ok {
-				d.error(errPhase)
-			}
-		}
-
-		// Figure out field corresponding to key.
-		var subv reflect.Value
-		destring := false // whether the value is wrapped in a string to be decoded first
-
-		if v.Kind() == reflect.Map {
-			elemType := v.Type().Elem()
-			if !mapElem.IsValid() {
-				mapElem = reflect.New(elemType).Elem()
-			} else {
-				mapElem.Set(reflect.Zero(elemType))
-			}
-			subv = mapElem
-		} else {
-			var f *field
-			fields := cachedTypeFields(v.Type())
-			for i := range fields {
-				ff := &fields[i]
-				if bytes.Equal(ff.nameBytes, key) {
-					f = ff
-					break
-				}
-				if f == nil && ff.equalFold(ff.nameBytes, key) {
-					f = ff
-				}
-			}
-			if f != nil {
-				subv = v
-				destring = f.quoted
-				for _, i := range f.index {
-					if subv.Kind() == reflect.Ptr {
-						if subv.IsNil() {
-							subv.Set(reflect.New(subv.Type().Elem()))
-						}
-						subv = subv.Elem()
-					}
-					subv = subv.Field(i)
-				}
-			}
-		}
-
-		// Read : before value.
-		if op == scanSkipSpace {
-			op = d.scanWhile(scanSkipSpace)
-		}
-		if op != scanObjectKey {
-			d.error(errPhase)
-		}
-
-		// Read value.
-		if destring {
-			switch qv := d.valueQuoted().(type) {
-			case nil:
-				d.literalStore(nullLiteral, subv, false)
-			case string:
-				d.literalStore([]byte(qv), subv, true)
-			default:
-				d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal unquoted value into %v", subv.Type()))
-			}
-		} else {
-			d.value(subv)
-		}
-
-		// Write value back to map;
-		// if using struct, subv points into struct already.
-		if v.Kind() == reflect.Map {
-			kt := v.Type().Key()
-			var kv reflect.Value
-			switch {
-			case kt.Kind() == reflect.String:
-				kv = reflect.ValueOf(key).Convert(v.Type().Key())
-			case reflect.PtrTo(kt).Implements(textUnmarshalerType):
-				kv = reflect.New(v.Type().Key())
-				d.literalStore(item, kv, true)
-				kv = kv.Elem()
-			default:
-				panic("json: Unexpected key type") // should never occur
-			}
-			v.SetMapIndex(kv, subv)
-		}
-
-		// Next token must be , or }.
-		op = d.scanWhile(scanSkipSpace)
-		if op == scanEndObject {
-			break
-		}
-		if op != scanObjectValue {
-			d.error(errPhase)
-		}
-	}
-}
-
-// isNull returns whether there's a null literal at the provided offset.
-func (d *decodeState) isNull(off int) bool {
-	if off+4 >= len(d.data) || d.data[off] != 'n' || d.data[off+1] != 'u' || d.data[off+2] != 'l' || d.data[off+3] != 'l' {
-		return false
-	}
-	d.nextscan.reset()
-	for i, c := range d.data[off:] {
-		if i > 4 {
-			return false
-		}
-		switch d.nextscan.step(&d.nextscan, c) {
-		case scanContinue, scanBeginName:
-			continue
-		}
-		break
-	}
-	return true
-}
-
-// name consumes a const or function from d.data[d.off-1:], decoding into the value v.
-// the first byte of the function name has been read already.
-func (d *decodeState) name(v reflect.Value) {
-	if d.isNull(d.off-1) {
-		d.literal(v)
-		return
-	}
-
-	// Check for unmarshaler.
-	u, ut, pv := d.indirect(v, false)
-	if d.storeKeyed(pv) {
-		return
-	}
-	if u != nil {
-		d.off--
-		err := u.UnmarshalJSON(d.next())
-		if err != nil {
-			d.error(err)
-		}
-		return
-	}
-	if ut != nil {
-		d.saveError(&UnmarshalTypeError{"object", v.Type(), int64(d.off)})
-		d.off--
-		d.next() // skip over function in input
-		return
-	}
-	v = pv
-
-	// Decoding into nil interface?  Switch to non-reflect code.
-	if v.Kind() == reflect.Interface && v.NumMethod() == 0 {
-		out := d.nameInterface()
-		if out == nil {
-			v.Set(reflect.Zero(v.Type()))
-		} else {
-			v.Set(reflect.ValueOf(out))
-		}
-		return
-	}
-
-	nameStart := d.off - 1
-
-	op := d.scanWhile(scanContinue)
-
-	name := d.data[nameStart : d.off-1]
-	if op != scanParam {
-		// Back up so the byte just read is consumed next.
-		d.off--
-		d.scan.undo(op)
-		if l, ok := d.convertLiteral(name); ok {
-			d.storeValue(v, l)
-			return
-		}
-		d.error(&SyntaxError{fmt.Sprintf("json: unknown constant %q", name), int64(d.off)})
-	}
-
-	funcName := string(name)
-	funcData := d.ext.funcs[funcName]
-	if funcData.key == "" {
-		d.error(fmt.Errorf("json: unknown function %q", funcName))
-	}
-
-	// Check type of target:
-	//   struct or
-	//   map[string]T or map[encoding.TextUnmarshaler]T
-	switch v.Kind() {
-	case reflect.Map:
-		// Map key must either have string kind or be an encoding.TextUnmarshaler.
-		t := v.Type()
-		if t.Key().Kind() != reflect.String &&
-			!reflect.PtrTo(t.Key()).Implements(textUnmarshalerType) {
-			d.saveError(&UnmarshalTypeError{"object", v.Type(), int64(d.off)})
-			d.off--
-			d.next() // skip over { } in input
-			return
-		}
-		if v.IsNil() {
-			v.Set(reflect.MakeMap(t))
-		}
-	case reflect.Struct:
-
-	default:
-		d.saveError(&UnmarshalTypeError{"object", v.Type(), int64(d.off)})
-		d.off--
-		d.next() // skip over { } in input
-		return
-	}
-
-	// TODO Fix case of func field as map.
-	//topv := v
-
-	// Figure out field corresponding to function.
-	key := []byte(funcData.key)
-	if v.Kind() == reflect.Map {
-		elemType := v.Type().Elem()
-		v = reflect.New(elemType).Elem()
-	} else {
-		var f *field
-		fields := cachedTypeFields(v.Type())
-		for i := range fields {
-			ff := &fields[i]
-			if bytes.Equal(ff.nameBytes, key) {
-				f = ff
-				break
-			}
-			if f == nil && ff.equalFold(ff.nameBytes, key) {
-				f = ff
-			}
-		}
-		if f != nil {
-			for _, i := range f.index {
-				if v.Kind() == reflect.Ptr {
-					if v.IsNil() {
-						v.Set(reflect.New(v.Type().Elem()))
-					}
-					v = v.Elem()
-				}
-				v = v.Field(i)
-			}
-			if v.Kind() == reflect.Ptr {
-				if v.IsNil() {
-					v.Set(reflect.New(v.Type().Elem()))
-				}
-				v = v.Elem()
-			}
-		}
-	}
-
-	// Check for unmarshaler on func field itself.
-	u, ut, pv = d.indirect(v, false)
-	if u != nil {
-		d.off = nameStart
-		err := u.UnmarshalJSON(d.next())
-		if err != nil {
-			d.error(err)
-		}
-		return
-	}
-
-	var mapElem reflect.Value
-
-	// Parse function arguments.
-	for i := 0; ; i++ {
-		// closing ) - can only happen on first iteration.
-		op := d.scanWhile(scanSkipSpace)
-		if op == scanEndParams {
-			break
-		}
-
-		// Back up so d.value can have the byte we just read.
-		d.off--
-		d.scan.undo(op)
-
-		if i >= len(funcData.args) {
-			d.error(fmt.Errorf("json: too many arguments for function %s", funcName))
-		}
-		key := []byte(funcData.args[i])
-
-		// Figure out field corresponding to key.
-		var subv reflect.Value
-		destring := false // whether the value is wrapped in a string to be decoded first
-
-		if v.Kind() == reflect.Map {
-			elemType := v.Type().Elem()
-			if !mapElem.IsValid() {
-				mapElem = reflect.New(elemType).Elem()
-			} else {
-				mapElem.Set(reflect.Zero(elemType))
-			}
-			subv = mapElem
-		} else {
-			var f *field
-			fields := cachedTypeFields(v.Type())
-			for i := range fields {
-				ff := &fields[i]
-				if bytes.Equal(ff.nameBytes, key) {
-					f = ff
-					break
-				}
-				if f == nil && ff.equalFold(ff.nameBytes, key) {
-					f = ff
-				}
-			}
-			if f != nil {
-				subv = v
-				destring = f.quoted
-				for _, i := range f.index {
-					if subv.Kind() == reflect.Ptr {
-						if subv.IsNil() {
-							subv.Set(reflect.New(subv.Type().Elem()))
-						}
-						subv = subv.Elem()
-					}
-					subv = subv.Field(i)
-				}
-			}
-		}
-
-		// Read value.
-		if destring {
-			switch qv := d.valueQuoted().(type) {
-			case nil:
-				d.literalStore(nullLiteral, subv, false)
-			case string:
-				d.literalStore([]byte(qv), subv, true)
-			default:
-				d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal unquoted value into %v", subv.Type()))
-			}
-		} else {
-			d.value(subv)
-		}
-
-		// Write value back to map;
-		// if using struct, subv points into struct already.
-		if v.Kind() == reflect.Map {
-			kt := v.Type().Key()
-			var kv reflect.Value
-			switch {
-			case kt.Kind() == reflect.String:
-				kv = reflect.ValueOf(key).Convert(v.Type().Key())
-			case reflect.PtrTo(kt).Implements(textUnmarshalerType):
-				kv = reflect.New(v.Type().Key())
-				d.literalStore(key, kv, true)
-				kv = kv.Elem()
-			default:
-				panic("json: Unexpected key type") // should never occur
-			}
-			v.SetMapIndex(kv, subv)
-		}
-
-		// Next token must be , or ).
-		op = d.scanWhile(scanSkipSpace)
-		if op == scanEndParams {
-			break
-		}
-		if op != scanParam {
-			d.error(errPhase)
-		}
-	}
-}
-
-// keyed attempts to decode an object or function using a keyed doc extension,
-// and returns the value and true on success, or nil and false otherwise.
-func (d *decodeState) keyed() (interface{}, bool) {
-	if len(d.ext.keyed) == 0 {
-		return nil, false
-	}
-
-	unquote := false
-
-	// Look-ahead first key to check for a keyed document extension.
-	d.nextscan.reset()
-	var start, end int
-	for i, c := range d.data[d.off-1:] {
-		switch op := d.nextscan.step(&d.nextscan, c); op {
-		case scanSkipSpace, scanContinue, scanBeginObject:
-			continue
-		case scanBeginLiteral, scanBeginName:
-			unquote = op == scanBeginLiteral
-			start = i
-			continue
-		}
-		end = i
-		break
-	}
-
-	name := d.data[d.off-1+start : d.off-1+end]
-
-	var key []byte
-	var ok bool
-	if unquote {
-		key, ok = unquoteBytes(name)
-		if !ok {
-			d.error(errPhase)
-		}
-	} else {
-		funcData, ok := d.ext.funcs[string(name)]
-		if !ok {
-			return nil, false
-		}
-		key = []byte(funcData.key)
-	}
-
-	decode, ok := d.ext.keyed[string(key)]
-	if !ok {
-		return nil, false
-	}
-
-	d.off--
-	out, err := decode(d.next())
-	if err != nil {
-		d.error(err)
-	}
-	return out, true
-}
-
-func (d *decodeState) storeKeyed(v reflect.Value) bool {
-	keyed, ok := d.keyed()
-	if !ok {
-		return false
-	}
-	d.storeValue(v, keyed)
-	return true
-}
-
-var (
-	trueBytes = []byte("true")
-	falseBytes = []byte("false")
-	nullBytes = []byte("null")
-)
-
-func (d *decodeState) storeValue(v reflect.Value, from interface{}) {
-	switch from {
-	case nil:
-		d.literalStore(nullBytes, v, false)
-		return
-	case true:
-		d.literalStore(trueBytes, v, false)
-		return
-	case false:
-		d.literalStore(falseBytes, v, false)
-		return
-	}
-	fromv := reflect.ValueOf(from)
-	for fromv.Kind() == reflect.Ptr && !fromv.IsNil() {
-		fromv = fromv.Elem()
-	}
-	fromt := fromv.Type()
-	for v.Kind() == reflect.Ptr && !v.IsNil() {
-		v = v.Elem()
-	}
-	vt := v.Type()
-	if fromt.AssignableTo(vt) {
-		v.Set(fromv)
-	} else if fromt.ConvertibleTo(vt) {
-		v.Set(fromv.Convert(vt))
-	} else {
-		d.saveError(&UnmarshalTypeError{"object", v.Type(), int64(d.off)})
-	}
-}
-
-func (d *decodeState) convertLiteral(name []byte) (interface{}, bool) {
-	if len(name) == 0 {
-		return nil, false
-	}
-	switch name[0] {
-	case 't':
-		if bytes.Equal(name, trueBytes) {
-			return true, true
-		}
-	case 'f':
-		if bytes.Equal(name, falseBytes) {
-			return false, true
-		}
-	case 'n':
-		if bytes.Equal(name, nullBytes) {
-			return nil, true
-		}
-	}
-	if l, ok := d.ext.consts[string(name)]; ok {
-		return l, true
-	}
-	return nil, false
-}
-
-// literal consumes a literal from d.data[d.off-1:], decoding into the value v.
-// The first byte of the literal has been read already
-// (that's how the caller knows it's a literal).
-func (d *decodeState) literal(v reflect.Value) {
-	// All bytes inside literal return scanContinue op code.
-	start := d.off - 1
-	op := d.scanWhile(scanContinue)
-
-	// Scan read one byte too far; back up.
-	d.off--
-	d.scan.undo(op)
-
-	d.literalStore(d.data[start:d.off], v, false)
-}
-
-// convertNumber converts the number literal s to a float64 or a Number
-// depending on the setting of d.useNumber.
-func (d *decodeState) convertNumber(s string) (interface{}, error) {
-	if d.useNumber {
-		return Number(s), nil
-	}
-	f, err := strconv.ParseFloat(s, 64)
-	if err != nil {
-		return nil, &UnmarshalTypeError{"number " + s, reflect.TypeOf(0.0), int64(d.off)}
-	}
-	return f, nil
-}
-
-var numberType = reflect.TypeOf(Number(""))
-
-// literalStore decodes a literal stored in item into v.
-//
-// fromQuoted indicates whether this literal came from unwrapping a
-// string from the ",string" struct tag option. this is used only to
-// produce more helpful error messages.
-func (d *decodeState) literalStore(item []byte, v reflect.Value, fromQuoted bool) {
-	// Check for unmarshaler.
-	if len(item) == 0 {
-		//Empty string given
-		d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
-		return
-	}
-	wantptr := item[0] == 'n' // null
-	u, ut, pv := d.indirect(v, wantptr)
-	if u != nil {
-		err := u.UnmarshalJSON(item)
-		if err != nil {
-			d.error(err)
-		}
-		return
-	}
-	if ut != nil {
-		if item[0] != '"' {
-			if fromQuoted {
-				d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
-			} else {
-				d.saveError(&UnmarshalTypeError{"string", v.Type(), int64(d.off)})
-			}
-			return
-		}
-		s, ok := unquoteBytes(item)
-		if !ok {
-			if fromQuoted {
-				d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
-			} else {
-				d.error(errPhase)
-			}
-		}
-		err := ut.UnmarshalText(s)
-		if err != nil {
-			d.error(err)
-		}
-		return
-	}
-
-	v = pv
-
-	switch c := item[0]; c {
-	case 'n': // null
-		switch v.Kind() {
-		case reflect.Interface, reflect.Ptr, reflect.Map, reflect.Slice:
-			v.Set(reflect.Zero(v.Type()))
-			// otherwise, ignore null for primitives/string
-		}
-	case 't', 'f': // true, false
-		value := c == 't'
-		switch v.Kind() {
-		default:
-			if fromQuoted {
-				d.saveError(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
-			} else {
-				d.saveError(&UnmarshalTypeError{"bool", v.Type(), int64(d.off)})
-			}
-		case reflect.Bool:
-			v.SetBool(value)
-		case reflect.Interface:
-			if v.NumMethod() == 0 {
-				v.Set(reflect.ValueOf(value))
-			} else {
-				d.saveError(&UnmarshalTypeError{"bool", v.Type(), int64(d.off)})
-			}
-		}
-
-	case '"': // string
-		s, ok := unquoteBytes(item)
-		if !ok {
-			if fromQuoted {
-				d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
-			} else {
-				d.error(errPhase)
-			}
-		}
-		switch v.Kind() {
-		default:
-			d.saveError(&UnmarshalTypeError{"string", v.Type(), int64(d.off)})
-		case reflect.Slice:
-			if v.Type().Elem().Kind() != reflect.Uint8 {
-				d.saveError(&UnmarshalTypeError{"string", v.Type(), int64(d.off)})
-				break
-			}
-			b := make([]byte, base64.StdEncoding.DecodedLen(len(s)))
-			n, err := base64.StdEncoding.Decode(b, s)
-			if err != nil {
-				d.saveError(err)
-				break
-			}
-			v.SetBytes(b[:n])
-		case reflect.String:
-			v.SetString(string(s))
-		case reflect.Interface:
-			if v.NumMethod() == 0 {
-				v.Set(reflect.ValueOf(string(s)))
-			} else {
-				d.saveError(&UnmarshalTypeError{"string", v.Type(), int64(d.off)})
-			}
-		}
-
-	default: // number
-		if c != '-' && (c < '0' || c > '9') {
-			if fromQuoted {
-				d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
-			} else {
-				d.error(errPhase)
-			}
-		}
-		s := string(item)
-		switch v.Kind() {
-		default:
-			if v.Kind() == reflect.String && v.Type() == numberType {
-				v.SetString(s)
-				if !isValidNumber(s) {
-					d.error(fmt.Errorf("json: invalid number literal, trying to unmarshal %q into Number", item))
-				}
-				break
-			}
-			if fromQuoted {
-				d.error(fmt.Errorf("json: invalid use of ,string struct tag, trying to unmarshal %q into %v", item, v.Type()))
-			} else {
-				d.error(&UnmarshalTypeError{"number", v.Type(), int64(d.off)})
-			}
-		case reflect.Interface:
-			n, err := d.convertNumber(s)
-			if err != nil {
-				d.saveError(err)
-				break
-			}
-			if v.NumMethod() != 0 {
-				d.saveError(&UnmarshalTypeError{"number", v.Type(), int64(d.off)})
-				break
-			}
-			v.Set(reflect.ValueOf(n))
-
-		case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-			n, err := strconv.ParseInt(s, 10, 64)
-			if err != nil || v.OverflowInt(n) {
-				d.saveError(&UnmarshalTypeError{"number " + s, v.Type(), int64(d.off)})
-				break
-			}
-			v.SetInt(n)
-
-		case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-			n, err := strconv.ParseUint(s, 10, 64)
-			if err != nil || v.OverflowUint(n) {
-				d.saveError(&UnmarshalTypeError{"number " + s, v.Type(), int64(d.off)})
-				break
-			}
-			v.SetUint(n)
-
-		case reflect.Float32, reflect.Float64:
-			n, err := strconv.ParseFloat(s, v.Type().Bits())
-			if err != nil || v.OverflowFloat(n) {
-				d.saveError(&UnmarshalTypeError{"number " + s, v.Type(), int64(d.off)})
-				break
-			}
-			v.SetFloat(n)
-		}
-	}
-}
-
-// The xxxInterface routines build up a value to be stored
-// in an empty interface. They are not strictly necessary,
-// but they avoid the weight of reflection in this common case.
-
-// valueInterface is like value but returns interface{}
-func (d *decodeState) valueInterface() interface{} {
-	switch d.scanWhile(scanSkipSpace) {
-	default:
-		d.error(errPhase)
-		panic("unreachable")
-	case scanBeginArray:
-		return d.arrayInterface()
-	case scanBeginObject:
-		return d.objectInterface()
-	case scanBeginLiteral:
-		return d.literalInterface()
-	case scanBeginName:
-		return d.nameInterface()
-	}
-}
-
-func (d *decodeState) syntaxError(expected string) {
-	msg := fmt.Sprintf("invalid character '%c' looking for %s", d.data[d.off-1], expected)
-	d.error(&SyntaxError{msg, int64(d.off)})
-}
-
-// arrayInterface is like array but returns []interface{}.
-func (d *decodeState) arrayInterface() []interface{} {
-	var v = make([]interface{}, 0)
-	for {
-		// Look ahead for ] - can only happen on first iteration.
-		op := d.scanWhile(scanSkipSpace)
-		if op == scanEndArray {
-			if len(v) > 0 && !d.ext.trailingCommas {
-				d.syntaxError("beginning of value")
-			}
-			break
-		}
-
-		// Back up so d.value can have the byte we just read.
-		d.off--
-		d.scan.undo(op)
-
-		v = append(v, d.valueInterface())
-
-		// Next token must be , or ].
-		op = d.scanWhile(scanSkipSpace)
-		if op == scanEndArray {
-			break
-		}
-		if op != scanArrayValue {
-			d.error(errPhase)
-		}
-	}
-	return v
-}
-
-// objectInterface is like object but returns map[string]interface{}.
-func (d *decodeState) objectInterface() interface{} {
-	v, ok := d.keyed()
-	if ok {
-		return v
-	}
-
-	m := make(map[string]interface{})
-	for {
-		// Read opening " of string key or closing }.
-		op := d.scanWhile(scanSkipSpace)
-		if op == scanEndObject {
-			if len(m) > 0 && !d.ext.trailingCommas {
-				d.syntaxError("beginning of object key string")
-			}
-			break
-		}
-		if op == scanBeginName {
-			if !d.ext.unquotedKeys {
-				d.syntaxError("beginning of object key string")
-			}
-		} else if op != scanBeginLiteral {
-			d.error(errPhase)
-		}
-		unquotedKey := op == scanBeginName
-
-		// Read string key.
-		start := d.off - 1
-		op = d.scanWhile(scanContinue)
-		item := d.data[start : d.off-1]
-		var key string
-		if unquotedKey {
-			key = string(item)
-		} else {
-			var ok bool
-			key, ok = unquote(item)
-			if !ok {
-				d.error(errPhase)
-			}
-		}
-
-		// Read : before value.
-		if op == scanSkipSpace {
-			op = d.scanWhile(scanSkipSpace)
-		}
-		if op != scanObjectKey {
-			d.error(errPhase)
-		}
-
-		// Read value.
-		m[key] = d.valueInterface()
-
-		// Next token must be , or }.
-		op = d.scanWhile(scanSkipSpace)
-		if op == scanEndObject {
-			break
-		}
-		if op != scanObjectValue {
-			d.error(errPhase)
-		}
-	}
-	return m
-}
-
-// literalInterface is like literal but returns an interface value.
-func (d *decodeState) literalInterface() interface{} {
-	// All bytes inside literal return scanContinue op code.
-	start := d.off - 1
-	op := d.scanWhile(scanContinue)
-
-	// Scan read one byte too far; back up.
-	d.off--
-	d.scan.undo(op)
-	item := d.data[start:d.off]
-
-	switch c := item[0]; c {
-	case 'n': // null
-		return nil
-
-	case 't', 'f': // true, false
-		return c == 't'
-
-	case '"': // string
-		s, ok := unquote(item)
-		if !ok {
-			d.error(errPhase)
-		}
-		return s
-
-	default: // number
-		if c != '-' && (c < '0' || c > '9') {
-			d.error(errPhase)
-		}
-		n, err := d.convertNumber(string(item))
-		if err != nil {
-			d.saveError(err)
-		}
-		return n
-	}
-}
-
-// nameInterface is like function but returns map[string]interface{}.
-func (d *decodeState) nameInterface() interface{} {
-	v, ok := d.keyed()
-	if ok {
-		return v
-	}
-
-	nameStart := d.off - 1
-
-	op := d.scanWhile(scanContinue)
-
-	name := d.data[nameStart : d.off-1]
-	if op != scanParam {
-		// Back up so the byte just read is consumed next.
-		d.off--
-		d.scan.undo(op)
-		if l, ok := d.convertLiteral(name); ok {
-			return l
-		}
-		d.error(&SyntaxError{fmt.Sprintf("json: unknown constant %q", name), int64(d.off)})
-	}
-
-	funcName := string(name)
-	funcData := d.ext.funcs[funcName]
-	if funcData.key == "" {
-		d.error(fmt.Errorf("json: unknown function %q", funcName))
-	}
-
-	m := make(map[string]interface{})
-	for i := 0; ; i++ {
-		// Look ahead for ) - can only happen on first iteration.
-		op := d.scanWhile(scanSkipSpace)
-		if op == scanEndParams {
-			break
-		}
-
-		// Back up so d.value can have the byte we just read.
-		d.off--
-		d.scan.undo(op)
-
-		if i >= len(funcData.args) {
-			d.error(fmt.Errorf("json: too many arguments for function %s", funcName))
-		}
-		m[funcData.args[i]] = d.valueInterface()
-
-		// Next token must be , or ).
-		op = d.scanWhile(scanSkipSpace)
-		if op == scanEndParams {
-			break
-		}
-		if op != scanParam {
-			d.error(errPhase)
-		}
-	}
-	return map[string]interface{}{funcData.key: m}
-}
-
-// getu4 decodes \uXXXX from the beginning of s, returning the hex value,
-// or it returns -1.
-func getu4(s []byte) rune {
-	if len(s) < 6 || s[0] != '\\' || s[1] != 'u' {
-		return -1
-	}
-	r, err := strconv.ParseUint(string(s[2:6]), 16, 64)
-	if err != nil {
-		return -1
-	}
-	return rune(r)
-}
-
-// unquote converts a quoted JSON string literal s into an actual string t.
-// The rules are different than for Go, so cannot use strconv.Unquote.
-func unquote(s []byte) (t string, ok bool) {
-	s, ok = unquoteBytes(s)
-	t = string(s)
-	return
-}
-
-func unquoteBytes(s []byte) (t []byte, ok bool) {
-	if len(s) < 2 || s[0] != '"' || s[len(s)-1] != '"' {
-		return
-	}
-	s = s[1 : len(s)-1]
-
-	// Check for unusual characters. If there are none,
-	// then no unquoting is needed, so return a slice of the
-	// original bytes.
-	r := 0
-	for r < len(s) {
-		c := s[r]
-		if c == '\\' || c == '"' || c < ' ' {
-			break
-		}
-		if c < utf8.RuneSelf {
-			r++
-			continue
-		}
-		rr, size := utf8.DecodeRune(s[r:])
-		if rr == utf8.RuneError && size == 1 {
-			break
-		}
-		r += size
-	}
-	if r == len(s) {
-		return s, true
-	}
-
-	b := make([]byte, len(s)+2*utf8.UTFMax)
-	w := copy(b, s[0:r])
-	for r < len(s) {
-		// Out of room?  Can only happen if s is full of
-		// malformed UTF-8 and we're replacing each
-		// byte with RuneError.
-		if w >= len(b)-2*utf8.UTFMax {
-			nb := make([]byte, (len(b)+utf8.UTFMax)*2)
-			copy(nb, b[0:w])
-			b = nb
-		}
-		switch c := s[r]; {
-		case c == '\\':
-			r++
-			if r >= len(s) {
-				return
-			}
-			switch s[r] {
-			default:
-				return
-			case '"', '\\', '/', '\'':
-				b[w] = s[r]
-				r++
-				w++
-			case 'b':
-				b[w] = '\b'
-				r++
-				w++
-			case 'f':
-				b[w] = '\f'
-				r++
-				w++
-			case 'n':
-				b[w] = '\n'
-				r++
-				w++
-			case 'r':
-				b[w] = '\r'
-				r++
-				w++
-			case 't':
-				b[w] = '\t'
-				r++
-				w++
-			case 'u':
-				r--
-				rr := getu4(s[r:])
-				if rr < 0 {
-					return
-				}
-				r += 6
-				if utf16.IsSurrogate(rr) {
-					rr1 := getu4(s[r:])
-					if dec := utf16.DecodeRune(rr, rr1); dec != unicode.ReplacementChar {
-						// A valid pair; consume.
-						r += 6
-						w += utf8.EncodeRune(b[w:], dec)
-						break
-					}
-					// Invalid surrogate; fall back to replacement rune.
-					rr = unicode.ReplacementChar
-				}
-				w += utf8.EncodeRune(b[w:], rr)
-			}
-
-		// Quote, control characters are invalid.
-		case c == '"', c < ' ':
-			return
-
-		// ASCII
-		case c < utf8.RuneSelf:
-			b[w] = c
-			r++
-			w++
-
-		// Coerce to well-formed UTF-8.
-		default:
-			rr, size := utf8.DecodeRune(s[r:])
-			r += size
-			w += utf8.EncodeRune(b[w:], rr)
-		}
-	}
-	return b[0:w], true
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/encode.go b/vendor/gopkg.in/mgo.v2/internal/json/encode.go
deleted file mode 100644
index 67a0f00..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/encode.go
+++ /dev/null
@@ -1,1256 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Package json implements encoding and decoding of JSON as defined in
-// RFC 4627. The mapping between JSON and Go values is described
-// in the documentation for the Marshal and Unmarshal functions.
-//
-// See "JSON and Go" for an introduction to this package:
-// https://golang.org/doc/articles/json_and_go.html
-package json
-
-import (
-	"bytes"
-	"encoding"
-	"encoding/base64"
-	"fmt"
-	"math"
-	"reflect"
-	"runtime"
-	"sort"
-	"strconv"
-	"strings"
-	"sync"
-	"unicode"
-	"unicode/utf8"
-)
-
-// Marshal returns the JSON encoding of v.
-//
-// Marshal traverses the value v recursively.
-// If an encountered value implements the Marshaler interface
-// and is not a nil pointer, Marshal calls its MarshalJSON method
-// to produce JSON. If no MarshalJSON method is present but the
-// value implements encoding.TextMarshaler instead, Marshal calls
-// its MarshalText method.
-// The nil pointer exception is not strictly necessary
-// but mimics a similar, necessary exception in the behavior of
-// UnmarshalJSON.
-//
-// Otherwise, Marshal uses the following type-dependent default encodings:
-//
-// Boolean values encode as JSON booleans.
-//
-// Floating point, integer, and Number values encode as JSON numbers.
-//
-// String values encode as JSON strings coerced to valid UTF-8,
-// replacing invalid bytes with the Unicode replacement rune.
-// The angle brackets "<" and ">" are escaped to "\u003c" and "\u003e"
-// to keep some browsers from misinterpreting JSON output as HTML.
-// Ampersand "&" is also escaped to "\u0026" for the same reason.
-// This escaping can be disabled using an Encoder with DisableHTMLEscaping.
-//
-// Array and slice values encode as JSON arrays, except that
-// []byte encodes as a base64-encoded string, and a nil slice
-// encodes as the null JSON value.
-//
-// Struct values encode as JSON objects. Each exported struct field
-// becomes a member of the object unless
-//   - the field's tag is "-", or
-//   - the field is empty and its tag specifies the "omitempty" option.
-// The empty values are false, 0, any
-// nil pointer or interface value, and any array, slice, map, or string of
-// length zero. The object's default key string is the struct field name
-// but can be specified in the struct field's tag value. The "json" key in
-// the struct field's tag value is the key name, followed by an optional comma
-// and options. Examples:
-//
-//   // Field is ignored by this package.
-//   Field int `json:"-"`
-//
-//   // Field appears in JSON as key "myName".
-//   Field int `json:"myName"`
-//
-//   // Field appears in JSON as key "myName" and
-//   // the field is omitted from the object if its value is empty,
-//   // as defined above.
-//   Field int `json:"myName,omitempty"`
-//
-//   // Field appears in JSON as key "Field" (the default), but
-//   // the field is skipped if empty.
-//   // Note the leading comma.
-//   Field int `json:",omitempty"`
-//
-// The "string" option signals that a field is stored as JSON inside a
-// JSON-encoded string. It applies only to fields of string, floating point,
-// integer, or boolean types. This extra level of encoding is sometimes used
-// when communicating with JavaScript programs:
-//
-//    Int64String int64 `json:",string"`
-//
-// The key name will be used if it's a non-empty string consisting of
-// only Unicode letters, digits, dollar signs, percent signs, hyphens,
-// underscores and slashes.
-//
-// Anonymous struct fields are usually marshaled as if their inner exported fields
-// were fields in the outer struct, subject to the usual Go visibility rules amended
-// as described in the next paragraph.
-// An anonymous struct field with a name given in its JSON tag is treated as
-// having that name, rather than being anonymous.
-// An anonymous struct field of interface type is treated the same as having
-// that type as its name, rather than being anonymous.
-//
-// The Go visibility rules for struct fields are amended for JSON when
-// deciding which field to marshal or unmarshal. If there are
-// multiple fields at the same level, and that level is the least
-// nested (and would therefore be the nesting level selected by the
-// usual Go rules), the following extra rules apply:
-//
-// 1) Of those fields, if any are JSON-tagged, only tagged fields are considered,
-// even if there are multiple untagged fields that would otherwise conflict.
-// 2) If there is exactly one field (tagged or not according to the first rule), that is selected.
-// 3) Otherwise there are multiple fields, and all are ignored; no error occurs.
-//
-// Handling of anonymous struct fields is new in Go 1.1.
-// Prior to Go 1.1, anonymous struct fields were ignored. To force ignoring of
-// an anonymous struct field in both current and earlier versions, give the field
-// a JSON tag of "-".
-//
-// Map values encode as JSON objects. The map's key type must either be a string
-// or implement encoding.TextMarshaler.  The map keys are used as JSON object
-// keys, subject to the UTF-8 coercion described for string values above.
-//
-// Pointer values encode as the value pointed to.
-// A nil pointer encodes as the null JSON value.
-//
-// Interface values encode as the value contained in the interface.
-// A nil interface value encodes as the null JSON value.
-//
-// Channel, complex, and function values cannot be encoded in JSON.
-// Attempting to encode such a value causes Marshal to return
-// an UnsupportedTypeError.
-//
-// JSON cannot represent cyclic data structures and Marshal does not
-// handle them. Passing cyclic structures to Marshal will result in
-// an infinite recursion.
-//
-func Marshal(v interface{}) ([]byte, error) {
-	e := &encodeState{}
-	err := e.marshal(v, encOpts{escapeHTML: true})
-	if err != nil {
-		return nil, err
-	}
-	return e.Bytes(), nil
-}
-
-// MarshalIndent is like Marshal but applies Indent to format the output.
-func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
-	b, err := Marshal(v)
-	if err != nil {
-		return nil, err
-	}
-	var buf bytes.Buffer
-	err = Indent(&buf, b, prefix, indent)
-	if err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
-}
-
-// HTMLEscape appends to dst the JSON-encoded src with <, >, &, U+2028 and U+2029
-// characters inside string literals changed to \u003c, \u003e, \u0026, \u2028, \u2029
-// so that the JSON will be safe to embed inside HTML <script> tags.
-// For historical reasons, web browsers don't honor standard HTML
-// escaping within <script> tags, so an alternative JSON encoding must
-// be used.
-func HTMLEscape(dst *bytes.Buffer, src []byte) {
-	// The characters can only appear in string literals,
-	// so just scan the string one byte at a time.
-	start := 0
-	for i, c := range src {
-		if c == '<' || c == '>' || c == '&' {
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			dst.WriteString(`\u00`)
-			dst.WriteByte(hex[c>>4])
-			dst.WriteByte(hex[c&0xF])
-			start = i + 1
-		}
-		// Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
-		if c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			dst.WriteString(`\u202`)
-			dst.WriteByte(hex[src[i+2]&0xF])
-			start = i + 3
-		}
-	}
-	if start < len(src) {
-		dst.Write(src[start:])
-	}
-}
-
-// Marshaler is the interface implemented by types that
-// can marshal themselves into valid JSON.
-type Marshaler interface {
-	MarshalJSON() ([]byte, error)
-}
-
-// An UnsupportedTypeError is returned by Marshal when attempting
-// to encode an unsupported value type.
-type UnsupportedTypeError struct {
-	Type reflect.Type
-}
-
-func (e *UnsupportedTypeError) Error() string {
-	return "json: unsupported type: " + e.Type.String()
-}
-
-type UnsupportedValueError struct {
-	Value reflect.Value
-	Str   string
-}
-
-func (e *UnsupportedValueError) Error() string {
-	return "json: unsupported value: " + e.Str
-}
-
-// Before Go 1.2, an InvalidUTF8Error was returned by Marshal when
-// attempting to encode a string value with invalid UTF-8 sequences.
-// As of Go 1.2, Marshal instead coerces the string to valid UTF-8 by
-// replacing invalid bytes with the Unicode replacement rune U+FFFD.
-// This error is no longer generated but is kept for backwards compatibility
-// with programs that might mention it.
-type InvalidUTF8Error struct {
-	S string // the whole string value that caused the error
-}
-
-func (e *InvalidUTF8Error) Error() string {
-	return "json: invalid UTF-8 in string: " + strconv.Quote(e.S)
-}
-
-type MarshalerError struct {
-	Type reflect.Type
-	Err  error
-}
-
-func (e *MarshalerError) Error() string {
-	return "json: error calling MarshalJSON for type " + e.Type.String() + ": " + e.Err.Error()
-}
-
-var hex = "0123456789abcdef"
-
-// An encodeState encodes JSON into a bytes.Buffer.
-type encodeState struct {
-	bytes.Buffer // accumulated output
-	scratch      [64]byte
-	ext          Extension
-}
-
-var encodeStatePool sync.Pool
-
-func newEncodeState() *encodeState {
-	if v := encodeStatePool.Get(); v != nil {
-		e := v.(*encodeState)
-		e.Reset()
-		return e
-	}
-	return new(encodeState)
-}
-
-func (e *encodeState) marshal(v interface{}, opts encOpts) (err error) {
-	defer func() {
-		if r := recover(); r != nil {
-			if _, ok := r.(runtime.Error); ok {
-				panic(r)
-			}
-			if s, ok := r.(string); ok {
-				panic(s)
-			}
-			err = r.(error)
-		}
-	}()
-	e.reflectValue(reflect.ValueOf(v), opts)
-	return nil
-}
-
-func (e *encodeState) error(err error) {
-	panic(err)
-}
-
-func isEmptyValue(v reflect.Value) bool {
-	switch v.Kind() {
-	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
-		return v.Len() == 0
-	case reflect.Bool:
-		return !v.Bool()
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		return v.Int() == 0
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		return v.Uint() == 0
-	case reflect.Float32, reflect.Float64:
-		return v.Float() == 0
-	case reflect.Interface, reflect.Ptr:
-		return v.IsNil()
-	}
-	return false
-}
-
-func (e *encodeState) reflectValue(v reflect.Value, opts encOpts) {
-	valueEncoder(v)(e, v, opts)
-}
-
-type encOpts struct {
-	// quoted causes primitive fields to be encoded inside JSON strings.
-	quoted bool
-	// escapeHTML causes '<', '>', and '&' to be escaped in JSON strings.
-	escapeHTML bool
-}
-
-type encoderFunc func(e *encodeState, v reflect.Value, opts encOpts)
-
-var encoderCache struct {
-	sync.RWMutex
-	m map[reflect.Type]encoderFunc
-}
-
-func valueEncoder(v reflect.Value) encoderFunc {
-	if !v.IsValid() {
-		return invalidValueEncoder
-	}
-	return typeEncoder(v.Type())
-}
-
-func typeEncoder(t reflect.Type) encoderFunc {
-	encoderCache.RLock()
-	f := encoderCache.m[t]
-	encoderCache.RUnlock()
-	if f != nil {
-		return f
-	}
-
-	// To deal with recursive types, populate the map with an
-	// indirect func before we build it. This type waits on the
-	// real func (f) to be ready and then calls it. This indirect
-	// func is only used for recursive types.
-	encoderCache.Lock()
-	if encoderCache.m == nil {
-		encoderCache.m = make(map[reflect.Type]encoderFunc)
-	}
-	var wg sync.WaitGroup
-	wg.Add(1)
-	encoderCache.m[t] = func(e *encodeState, v reflect.Value, opts encOpts) {
-		wg.Wait()
-		f(e, v, opts)
-	}
-	encoderCache.Unlock()
-
-	// Compute fields without lock.
-	// Might duplicate effort but won't hold other computations back.
-	innerf := newTypeEncoder(t, true)
-	f = func(e *encodeState, v reflect.Value, opts encOpts) {
-		encode, ok := e.ext.encode[v.Type()]
-		if !ok {
-			innerf(e, v, opts)
-			return
-		}
-
-		b, err := encode(v.Interface())
-		if err == nil {
-			// copy JSON into buffer, checking validity.
-			err = compact(&e.Buffer, b, opts.escapeHTML)
-		}
-		if err != nil {
-			e.error(&MarshalerError{v.Type(), err})
-		}
-	}
-	wg.Done()
-	encoderCache.Lock()
-	encoderCache.m[t] = f
-	encoderCache.Unlock()
-	return f
-}
-
-var (
-	marshalerType     = reflect.TypeOf(new(Marshaler)).Elem()
-	textMarshalerType = reflect.TypeOf(new(encoding.TextMarshaler)).Elem()
-)
-
-// newTypeEncoder constructs an encoderFunc for a type.
-// The returned encoder only checks CanAddr when allowAddr is true.
-func newTypeEncoder(t reflect.Type, allowAddr bool) encoderFunc {
-	if t.Implements(marshalerType) {
-		return marshalerEncoder
-	}
-	if t.Kind() != reflect.Ptr && allowAddr {
-		if reflect.PtrTo(t).Implements(marshalerType) {
-			return newCondAddrEncoder(addrMarshalerEncoder, newTypeEncoder(t, false))
-		}
-	}
-
-	if t.Implements(textMarshalerType) {
-		return textMarshalerEncoder
-	}
-	if t.Kind() != reflect.Ptr && allowAddr {
-		if reflect.PtrTo(t).Implements(textMarshalerType) {
-			return newCondAddrEncoder(addrTextMarshalerEncoder, newTypeEncoder(t, false))
-		}
-	}
-
-	switch t.Kind() {
-	case reflect.Bool:
-		return boolEncoder
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		return intEncoder
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
-		return uintEncoder
-	case reflect.Float32:
-		return float32Encoder
-	case reflect.Float64:
-		return float64Encoder
-	case reflect.String:
-		return stringEncoder
-	case reflect.Interface:
-		return interfaceEncoder
-	case reflect.Struct:
-		return newStructEncoder(t)
-	case reflect.Map:
-		return newMapEncoder(t)
-	case reflect.Slice:
-		return newSliceEncoder(t)
-	case reflect.Array:
-		return newArrayEncoder(t)
-	case reflect.Ptr:
-		return newPtrEncoder(t)
-	default:
-		return unsupportedTypeEncoder
-	}
-}
-
-func invalidValueEncoder(e *encodeState, v reflect.Value, _ encOpts) {
-	e.WriteString("null")
-}
-
-func marshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.Kind() == reflect.Ptr && v.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	m := v.Interface().(Marshaler)
-	b, err := m.MarshalJSON()
-	if err == nil {
-		// copy JSON into buffer, checking validity.
-		err = compact(&e.Buffer, b, opts.escapeHTML)
-	}
-	if err != nil {
-		e.error(&MarshalerError{v.Type(), err})
-	}
-}
-
-func addrMarshalerEncoder(e *encodeState, v reflect.Value, _ encOpts) {
-	va := v.Addr()
-	if va.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	m := va.Interface().(Marshaler)
-	b, err := m.MarshalJSON()
-	if err == nil {
-		// copy JSON into buffer, checking validity.
-		err = compact(&e.Buffer, b, true)
-	}
-	if err != nil {
-		e.error(&MarshalerError{v.Type(), err})
-	}
-}
-
-func textMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.Kind() == reflect.Ptr && v.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	m := v.Interface().(encoding.TextMarshaler)
-	b, err := m.MarshalText()
-	if err != nil {
-		e.error(&MarshalerError{v.Type(), err})
-	}
-	e.stringBytes(b, opts.escapeHTML)
-}
-
-func addrTextMarshalerEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	va := v.Addr()
-	if va.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	m := va.Interface().(encoding.TextMarshaler)
-	b, err := m.MarshalText()
-	if err != nil {
-		e.error(&MarshalerError{v.Type(), err})
-	}
-	e.stringBytes(b, opts.escapeHTML)
-}
-
-func boolEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-	if v.Bool() {
-		e.WriteString("true")
-	} else {
-		e.WriteString("false")
-	}
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-}
-
-func intEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	b := strconv.AppendInt(e.scratch[:0], v.Int(), 10)
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-	e.Write(b)
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-}
-
-func uintEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	b := strconv.AppendUint(e.scratch[:0], v.Uint(), 10)
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-	e.Write(b)
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-}
-
-type floatEncoder int // number of bits
-
-func (bits floatEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
-	f := v.Float()
-	if math.IsInf(f, 0) || math.IsNaN(f) {
-		e.error(&UnsupportedValueError{v, strconv.FormatFloat(f, 'g', -1, int(bits))})
-	}
-	b := strconv.AppendFloat(e.scratch[:0], f, 'g', -1, int(bits))
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-	e.Write(b)
-	if opts.quoted {
-		e.WriteByte('"')
-	}
-}
-
-var (
-	float32Encoder = (floatEncoder(32)).encode
-	float64Encoder = (floatEncoder(64)).encode
-)
-
-func stringEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.Type() == numberType {
-		numStr := v.String()
-		// In Go1.5 the empty string encodes to "0", while this is not a valid number literal
-		// we keep compatibility so check validity after this.
-		if numStr == "" {
-			numStr = "0" // Number's zero-val
-		}
-		if !isValidNumber(numStr) {
-			e.error(fmt.Errorf("json: invalid number literal %q", numStr))
-		}
-		e.WriteString(numStr)
-		return
-	}
-	if opts.quoted {
-		sb, err := Marshal(v.String())
-		if err != nil {
-			e.error(err)
-		}
-		e.string(string(sb), opts.escapeHTML)
-	} else {
-		e.string(v.String(), opts.escapeHTML)
-	}
-}
-
-func interfaceEncoder(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	e.reflectValue(v.Elem(), opts)
-}
-
-func unsupportedTypeEncoder(e *encodeState, v reflect.Value, _ encOpts) {
-	e.error(&UnsupportedTypeError{v.Type()})
-}
-
-type structEncoder struct {
-	fields    []field
-	fieldEncs []encoderFunc
-}
-
-func (se *structEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
-	e.WriteByte('{')
-	first := true
-	for i, f := range se.fields {
-		fv := fieldByIndex(v, f.index)
-		if !fv.IsValid() || f.omitEmpty && isEmptyValue(fv) {
-			continue
-		}
-		if first {
-			first = false
-		} else {
-			e.WriteByte(',')
-		}
-		e.string(f.name, opts.escapeHTML)
-		e.WriteByte(':')
-		opts.quoted = f.quoted
-		se.fieldEncs[i](e, fv, opts)
-	}
-	e.WriteByte('}')
-}
-
-func newStructEncoder(t reflect.Type) encoderFunc {
-	fields := cachedTypeFields(t)
-	se := &structEncoder{
-		fields:    fields,
-		fieldEncs: make([]encoderFunc, len(fields)),
-	}
-	for i, f := range fields {
-		se.fieldEncs[i] = typeEncoder(typeByIndex(t, f.index))
-	}
-	return se.encode
-}
-
-type mapEncoder struct {
-	elemEnc encoderFunc
-}
-
-func (me *mapEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	e.WriteByte('{')
-
-	// Extract and sort the keys.
-	keys := v.MapKeys()
-	sv := make([]reflectWithString, len(keys))
-	for i, v := range keys {
-		sv[i].v = v
-		if err := sv[i].resolve(); err != nil {
-			e.error(&MarshalerError{v.Type(), err})
-		}
-	}
-	sort.Sort(byString(sv))
-
-	for i, kv := range sv {
-		if i > 0 {
-			e.WriteByte(',')
-		}
-		e.string(kv.s, opts.escapeHTML)
-		e.WriteByte(':')
-		me.elemEnc(e, v.MapIndex(kv.v), opts)
-	}
-	e.WriteByte('}')
-}
-
-func newMapEncoder(t reflect.Type) encoderFunc {
-	if t.Key().Kind() != reflect.String && !t.Key().Implements(textMarshalerType) {
-		return unsupportedTypeEncoder
-	}
-	me := &mapEncoder{typeEncoder(t.Elem())}
-	return me.encode
-}
-
-func encodeByteSlice(e *encodeState, v reflect.Value, _ encOpts) {
-	if v.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	s := v.Bytes()
-	e.WriteByte('"')
-	if len(s) < 1024 {
-		// for small buffers, using Encode directly is much faster.
-		dst := make([]byte, base64.StdEncoding.EncodedLen(len(s)))
-		base64.StdEncoding.Encode(dst, s)
-		e.Write(dst)
-	} else {
-		// for large buffers, avoid unnecessary extra temporary
-		// buffer space.
-		enc := base64.NewEncoder(base64.StdEncoding, e)
-		enc.Write(s)
-		enc.Close()
-	}
-	e.WriteByte('"')
-}
-
-// sliceEncoder just wraps an arrayEncoder, checking to make sure the value isn't nil.
-type sliceEncoder struct {
-	arrayEnc encoderFunc
-}
-
-func (se *sliceEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	se.arrayEnc(e, v, opts)
-}
-
-func newSliceEncoder(t reflect.Type) encoderFunc {
-	// Byte slices get special treatment; arrays don't.
-	if t.Elem().Kind() == reflect.Uint8 &&
-		!t.Elem().Implements(marshalerType) &&
-		!t.Elem().Implements(textMarshalerType) {
-		return encodeByteSlice
-	}
-	enc := &sliceEncoder{newArrayEncoder(t)}
-	return enc.encode
-}
-
-type arrayEncoder struct {
-	elemEnc encoderFunc
-}
-
-func (ae *arrayEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
-	e.WriteByte('[')
-	n := v.Len()
-	for i := 0; i < n; i++ {
-		if i > 0 {
-			e.WriteByte(',')
-		}
-		ae.elemEnc(e, v.Index(i), opts)
-	}
-	e.WriteByte(']')
-}
-
-func newArrayEncoder(t reflect.Type) encoderFunc {
-	enc := &arrayEncoder{typeEncoder(t.Elem())}
-	return enc.encode
-}
-
-type ptrEncoder struct {
-	elemEnc encoderFunc
-}
-
-func (pe *ptrEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.IsNil() {
-		e.WriteString("null")
-		return
-	}
-	pe.elemEnc(e, v.Elem(), opts)
-}
-
-func newPtrEncoder(t reflect.Type) encoderFunc {
-	enc := &ptrEncoder{typeEncoder(t.Elem())}
-	return enc.encode
-}
-
-type condAddrEncoder struct {
-	canAddrEnc, elseEnc encoderFunc
-}
-
-func (ce *condAddrEncoder) encode(e *encodeState, v reflect.Value, opts encOpts) {
-	if v.CanAddr() {
-		ce.canAddrEnc(e, v, opts)
-	} else {
-		ce.elseEnc(e, v, opts)
-	}
-}
-
-// newCondAddrEncoder returns an encoder that checks whether its value
-// CanAddr and delegates to canAddrEnc if so, else to elseEnc.
-func newCondAddrEncoder(canAddrEnc, elseEnc encoderFunc) encoderFunc {
-	enc := &condAddrEncoder{canAddrEnc: canAddrEnc, elseEnc: elseEnc}
-	return enc.encode
-}
-
-func isValidTag(s string) bool {
-	if s == "" {
-		return false
-	}
-	for _, c := range s {
-		switch {
-		case strings.ContainsRune("!#$%&()*+-./:<=>?@[]^_{|}~ ", c):
-			// Backslash and quote chars are reserved, but
-			// otherwise any punctuation chars are allowed
-			// in a tag name.
-		default:
-			if !unicode.IsLetter(c) && !unicode.IsDigit(c) {
-				return false
-			}
-		}
-	}
-	return true
-}
-
-func fieldByIndex(v reflect.Value, index []int) reflect.Value {
-	for _, i := range index {
-		if v.Kind() == reflect.Ptr {
-			if v.IsNil() {
-				return reflect.Value{}
-			}
-			v = v.Elem()
-		}
-		v = v.Field(i)
-	}
-	return v
-}
-
-func typeByIndex(t reflect.Type, index []int) reflect.Type {
-	for _, i := range index {
-		if t.Kind() == reflect.Ptr {
-			t = t.Elem()
-		}
-		t = t.Field(i).Type
-	}
-	return t
-}
-
-type reflectWithString struct {
-	v reflect.Value
-	s string
-}
-
-func (w *reflectWithString) resolve() error {
-	if w.v.Kind() == reflect.String {
-		w.s = w.v.String()
-		return nil
-	}
-	buf, err := w.v.Interface().(encoding.TextMarshaler).MarshalText()
-	w.s = string(buf)
-	return err
-}
-
-// byString is a slice of reflectWithString where the reflect.Value is either
-// a string or an encoding.TextMarshaler.
-// It implements the methods to sort by string.
-type byString []reflectWithString
-
-func (sv byString) Len() int           { return len(sv) }
-func (sv byString) Swap(i, j int)      { sv[i], sv[j] = sv[j], sv[i] }
-func (sv byString) Less(i, j int) bool { return sv[i].s < sv[j].s }
-
-// NOTE: keep in sync with stringBytes below.
-func (e *encodeState) string(s string, escapeHTML bool) int {
-	len0 := e.Len()
-	e.WriteByte('"')
-	start := 0
-	for i := 0; i < len(s); {
-		if b := s[i]; b < utf8.RuneSelf {
-			if 0x20 <= b && b != '\\' && b != '"' &&
-				(!escapeHTML || b != '<' && b != '>' && b != '&') {
-				i++
-				continue
-			}
-			if start < i {
-				e.WriteString(s[start:i])
-			}
-			switch b {
-			case '\\', '"':
-				e.WriteByte('\\')
-				e.WriteByte(b)
-			case '\n':
-				e.WriteByte('\\')
-				e.WriteByte('n')
-			case '\r':
-				e.WriteByte('\\')
-				e.WriteByte('r')
-			case '\t':
-				e.WriteByte('\\')
-				e.WriteByte('t')
-			default:
-				// This encodes bytes < 0x20 except for \t, \n and \r.
-				// If escapeHTML is set, it also escapes <, >, and &
-				// because they can lead to security holes when
-				// user-controlled strings are rendered into JSON
-				// and served to some browsers.
-				e.WriteString(`\u00`)
-				e.WriteByte(hex[b>>4])
-				e.WriteByte(hex[b&0xF])
-			}
-			i++
-			start = i
-			continue
-		}
-		c, size := utf8.DecodeRuneInString(s[i:])
-		if c == utf8.RuneError && size == 1 {
-			if start < i {
-				e.WriteString(s[start:i])
-			}
-			e.WriteString(`\ufffd`)
-			i += size
-			start = i
-			continue
-		}
-		// U+2028 is LINE SEPARATOR.
-		// U+2029 is PARAGRAPH SEPARATOR.
-		// They are both technically valid characters in JSON strings,
-		// but don't work in JSONP, which has to be evaluated as JavaScript,
-		// and can lead to security holes there. It is valid JSON to
-		// escape them, so we do so unconditionally.
-		// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
-		if c == '\u2028' || c == '\u2029' {
-			if start < i {
-				e.WriteString(s[start:i])
-			}
-			e.WriteString(`\u202`)
-			e.WriteByte(hex[c&0xF])
-			i += size
-			start = i
-			continue
-		}
-		i += size
-	}
-	if start < len(s) {
-		e.WriteString(s[start:])
-	}
-	e.WriteByte('"')
-	return e.Len() - len0
-}
-
-// NOTE: keep in sync with string above.
-func (e *encodeState) stringBytes(s []byte, escapeHTML bool) int {
-	len0 := e.Len()
-	e.WriteByte('"')
-	start := 0
-	for i := 0; i < len(s); {
-		if b := s[i]; b < utf8.RuneSelf {
-			if 0x20 <= b && b != '\\' && b != '"' &&
-				(!escapeHTML || b != '<' && b != '>' && b != '&') {
-				i++
-				continue
-			}
-			if start < i {
-				e.Write(s[start:i])
-			}
-			switch b {
-			case '\\', '"':
-				e.WriteByte('\\')
-				e.WriteByte(b)
-			case '\n':
-				e.WriteByte('\\')
-				e.WriteByte('n')
-			case '\r':
-				e.WriteByte('\\')
-				e.WriteByte('r')
-			case '\t':
-				e.WriteByte('\\')
-				e.WriteByte('t')
-			default:
-				// This encodes bytes < 0x20 except for \t, \n and \r.
-				// If escapeHTML is set, it also escapes <, >, and &
-				// because they can lead to security holes when
-				// user-controlled strings are rendered into JSON
-				// and served to some browsers.
-				e.WriteString(`\u00`)
-				e.WriteByte(hex[b>>4])
-				e.WriteByte(hex[b&0xF])
-			}
-			i++
-			start = i
-			continue
-		}
-		c, size := utf8.DecodeRune(s[i:])
-		if c == utf8.RuneError && size == 1 {
-			if start < i {
-				e.Write(s[start:i])
-			}
-			e.WriteString(`\ufffd`)
-			i += size
-			start = i
-			continue
-		}
-		// U+2028 is LINE SEPARATOR.
-		// U+2029 is PARAGRAPH SEPARATOR.
-		// They are both technically valid characters in JSON strings,
-		// but don't work in JSONP, which has to be evaluated as JavaScript,
-		// and can lead to security holes there. It is valid JSON to
-		// escape them, so we do so unconditionally.
-		// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
-		if c == '\u2028' || c == '\u2029' {
-			if start < i {
-				e.Write(s[start:i])
-			}
-			e.WriteString(`\u202`)
-			e.WriteByte(hex[c&0xF])
-			i += size
-			start = i
-			continue
-		}
-		i += size
-	}
-	if start < len(s) {
-		e.Write(s[start:])
-	}
-	e.WriteByte('"')
-	return e.Len() - len0
-}
-
-// A field represents a single field found in a struct.
-type field struct {
-	name      string
-	nameBytes []byte                 // []byte(name)
-	equalFold func(s, t []byte) bool // bytes.EqualFold or equivalent
-
-	tag       bool
-	index     []int
-	typ       reflect.Type
-	omitEmpty bool
-	quoted    bool
-}
-
-func fillField(f field) field {
-	f.nameBytes = []byte(f.name)
-	f.equalFold = foldFunc(f.nameBytes)
-	return f
-}
-
-// byName sorts field by name, breaking ties with depth,
-// then breaking ties with "name came from json tag", then
-// breaking ties with index sequence.
-type byName []field
-
-func (x byName) Len() int { return len(x) }
-
-func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
-
-func (x byName) Less(i, j int) bool {
-	if x[i].name != x[j].name {
-		return x[i].name < x[j].name
-	}
-	if len(x[i].index) != len(x[j].index) {
-		return len(x[i].index) < len(x[j].index)
-	}
-	if x[i].tag != x[j].tag {
-		return x[i].tag
-	}
-	return byIndex(x).Less(i, j)
-}
-
-// byIndex sorts field by index sequence.
-type byIndex []field
-
-func (x byIndex) Len() int { return len(x) }
-
-func (x byIndex) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
-
-func (x byIndex) Less(i, j int) bool {
-	for k, xik := range x[i].index {
-		if k >= len(x[j].index) {
-			return false
-		}
-		if xik != x[j].index[k] {
-			return xik < x[j].index[k]
-		}
-	}
-	return len(x[i].index) < len(x[j].index)
-}
-
-// typeFields returns a list of fields that JSON should recognize for the given type.
-// The algorithm is breadth-first search over the set of structs to include - the top struct
-// and then any reachable anonymous structs.
-func typeFields(t reflect.Type) []field {
-	// Anonymous fields to explore at the current level and the next.
-	current := []field{}
-	next := []field{{typ: t}}
-
-	// Count of queued names for current level and the next.
-	count := map[reflect.Type]int{}
-	nextCount := map[reflect.Type]int{}
-
-	// Types already visited at an earlier level.
-	visited := map[reflect.Type]bool{}
-
-	// Fields found.
-	var fields []field
-
-	for len(next) > 0 {
-		current, next = next, current[:0]
-		count, nextCount = nextCount, map[reflect.Type]int{}
-
-		for _, f := range current {
-			if visited[f.typ] {
-				continue
-			}
-			visited[f.typ] = true
-
-			// Scan f.typ for fields to include.
-			for i := 0; i < f.typ.NumField(); i++ {
-				sf := f.typ.Field(i)
-				if sf.PkgPath != "" && !sf.Anonymous { // unexported
-					continue
-				}
-				tag := sf.Tag.Get("json")
-				if tag == "-" {
-					continue
-				}
-				name, opts := parseTag(tag)
-				if !isValidTag(name) {
-					name = ""
-				}
-				index := make([]int, len(f.index)+1)
-				copy(index, f.index)
-				index[len(f.index)] = i
-
-				ft := sf.Type
-				if ft.Name() == "" && ft.Kind() == reflect.Ptr {
-					// Follow pointer.
-					ft = ft.Elem()
-				}
-
-				// Only strings, floats, integers, and booleans can be quoted.
-				quoted := false
-				if opts.Contains("string") {
-					switch ft.Kind() {
-					case reflect.Bool,
-						reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64,
-						reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64,
-						reflect.Float32, reflect.Float64,
-						reflect.String:
-						quoted = true
-					}
-				}
-
-				// Record found field and index sequence.
-				if name != "" || !sf.Anonymous || ft.Kind() != reflect.Struct {
-					tagged := name != ""
-					if name == "" {
-						name = sf.Name
-					}
-					fields = append(fields, fillField(field{
-						name:      name,
-						tag:       tagged,
-						index:     index,
-						typ:       ft,
-						omitEmpty: opts.Contains("omitempty"),
-						quoted:    quoted,
-					}))
-					if count[f.typ] > 1 {
-						// If there were multiple instances, add a second,
-						// so that the annihilation code will see a duplicate.
-						// It only cares about the distinction between 1 or 2,
-						// so don't bother generating any more copies.
-						fields = append(fields, fields[len(fields)-1])
-					}
-					continue
-				}
-
-				// Record new anonymous struct to explore in next round.
-				nextCount[ft]++
-				if nextCount[ft] == 1 {
-					next = append(next, fillField(field{name: ft.Name(), index: index, typ: ft}))
-				}
-			}
-		}
-	}
-
-	sort.Sort(byName(fields))
-
-	// Delete all fields that are hidden by the Go rules for embedded fields,
-	// except that fields with JSON tags are promoted.
-
-	// The fields are sorted in primary order of name, secondary order
-	// of field index length. Loop over names; for each name, delete
-	// hidden fields by choosing the one dominant field that survives.
-	out := fields[:0]
-	for advance, i := 0, 0; i < len(fields); i += advance {
-		// One iteration per name.
-		// Find the sequence of fields with the name of this first field.
-		fi := fields[i]
-		name := fi.name
-		for advance = 1; i+advance < len(fields); advance++ {
-			fj := fields[i+advance]
-			if fj.name != name {
-				break
-			}
-		}
-		if advance == 1 { // Only one field with this name
-			out = append(out, fi)
-			continue
-		}
-		dominant, ok := dominantField(fields[i : i+advance])
-		if ok {
-			out = append(out, dominant)
-		}
-	}
-
-	fields = out
-	sort.Sort(byIndex(fields))
-
-	return fields
-}
-
-// dominantField looks through the fields, all of which are known to
-// have the same name, to find the single field that dominates the
-// others using Go's embedding rules, modified by the presence of
-// JSON tags. If there are multiple top-level fields, the boolean
-// will be false: This condition is an error in Go and we skip all
-// the fields.
-func dominantField(fields []field) (field, bool) {
-	// The fields are sorted in increasing index-length order. The winner
-	// must therefore be one with the shortest index length. Drop all
-	// longer entries, which is easy: just truncate the slice.
-	length := len(fields[0].index)
-	tagged := -1 // Index of first tagged field.
-	for i, f := range fields {
-		if len(f.index) > length {
-			fields = fields[:i]
-			break
-		}
-		if f.tag {
-			if tagged >= 0 {
-				// Multiple tagged fields at the same level: conflict.
-				// Return no field.
-				return field{}, false
-			}
-			tagged = i
-		}
-	}
-	if tagged >= 0 {
-		return fields[tagged], true
-	}
-	// All remaining fields have the same length. If there's more than one,
-	// we have a conflict (two fields named "X" at the same level) and we
-	// return no field.
-	if len(fields) > 1 {
-		return field{}, false
-	}
-	return fields[0], true
-}
-
-var fieldCache struct {
-	sync.RWMutex
-	m map[reflect.Type][]field
-}
-
-// cachedTypeFields is like typeFields but uses a cache to avoid repeated work.
-func cachedTypeFields(t reflect.Type) []field {
-	fieldCache.RLock()
-	f := fieldCache.m[t]
-	fieldCache.RUnlock()
-	if f != nil {
-		return f
-	}
-
-	// Compute fields without lock.
-	// Might duplicate effort but won't hold other computations back.
-	f = typeFields(t)
-	if f == nil {
-		f = []field{}
-	}
-
-	fieldCache.Lock()
-	if fieldCache.m == nil {
-		fieldCache.m = map[reflect.Type][]field{}
-	}
-	fieldCache.m[t] = f
-	fieldCache.Unlock()
-	return f
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/extension.go b/vendor/gopkg.in/mgo.v2/internal/json/extension.go
deleted file mode 100644
index 1c8fd45..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/extension.go
+++ /dev/null
@@ -1,95 +0,0 @@
-package json
-
-import (
-	"reflect"
-)
-
-// Extension holds a set of additional rules to be used when unmarshaling
-// strict JSON or JSON-like content.
-type Extension struct {
-	funcs  map[string]funcExt
-	consts map[string]interface{}
-	keyed  map[string]func([]byte) (interface{}, error)
-	encode map[reflect.Type]func(v interface{}) ([]byte, error)
-
-	unquotedKeys   bool
-	trailingCommas bool
-}
-
-type funcExt struct {
-	key  string
-	args []string
-}
-
-// Extend changes the decoder behavior to consider the provided extension.
-func (dec *Decoder) Extend(ext *Extension) { dec.d.ext = *ext }
-
-// Extend changes the encoder behavior to consider the provided extension.
-func (enc *Encoder) Extend(ext *Extension) { enc.ext = *ext }
-
-// Extend includes in e the extensions defined in ext.
-func (e *Extension) Extend(ext *Extension) {
-	for name, fext := range ext.funcs {
-		e.DecodeFunc(name, fext.key, fext.args...)
-	}
-	for name, value := range ext.consts {
-		e.DecodeConst(name, value)
-	}
-	for key, decode := range ext.keyed {
-		e.DecodeKeyed(key, decode)
-	}
-	for typ, encode := range ext.encode {
-		if e.encode == nil {
-			e.encode = make(map[reflect.Type]func(v interface{}) ([]byte, error))
-		}
-		e.encode[typ] = encode
-	}
-}
-
-// DecodeFunc defines a function call that may be observed inside JSON content.
-// A function with the provided name will be unmarshaled as the document
-// {key: {args[0]: ..., args[N]: ...}}.
-func (e *Extension) DecodeFunc(name string, key string, args ...string) {
-	if e.funcs == nil {
-		e.funcs = make(map[string]funcExt)
-	}
-	e.funcs[name] = funcExt{key, args}
-}
-
-// DecodeConst defines a constant name that may be observed inside JSON content
-// and will be decoded with the provided value.
-func (e *Extension) DecodeConst(name string, value interface{}) {
-	if e.consts == nil {
-		e.consts = make(map[string]interface{})
-	}
-	e.consts[name] = value
-}
-
-// DecodeKeyed defines a key that when observed as the first element inside a
-// JSON document triggers the decoding of that document via the provided
-// decode function.
-func (e *Extension) DecodeKeyed(key string, decode func(data []byte) (interface{}, error)) {
-	if e.keyed == nil {
-		e.keyed = make(map[string]func([]byte) (interface{}, error))
-	}
-	e.keyed[key] = decode
-}
-
-// DecodeUnquotedKeys defines whether to accept map keys that are unquoted strings.
-func (e *Extension) DecodeUnquotedKeys(accept bool) {
-	e.unquotedKeys = accept
-}
-
-// DecodeTrailingCommas defines whether to accept trailing commas in maps and arrays.
-func (e *Extension) DecodeTrailingCommas(accept bool) {
-	e.trailingCommas = accept
-}
-
-// EncodeType registers a function to encode values with the same type of the
-// provided sample.
-func (e *Extension) EncodeType(sample interface{}, encode func(v interface{}) ([]byte, error)) {
-	if e.encode == nil {
-		e.encode = make(map[reflect.Type]func(v interface{}) ([]byte, error))
-	}
-	e.encode[reflect.TypeOf(sample)] = encode
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/fold.go b/vendor/gopkg.in/mgo.v2/internal/json/fold.go
deleted file mode 100644
index 9e17012..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/fold.go
+++ /dev/null
@@ -1,143 +0,0 @@
-// Copyright 2013 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import (
-	"bytes"
-	"unicode/utf8"
-)
-
-const (
-	caseMask     = ^byte(0x20) // Mask to ignore case in ASCII.
-	kelvin       = '\u212a'
-	smallLongEss = '\u017f'
-)
-
-// foldFunc returns one of four different case folding equivalence
-// functions, from most general (and slow) to fastest:
-//
-// 1) bytes.EqualFold, if the key s contains any non-ASCII UTF-8
-// 2) equalFoldRight, if s contains special folding ASCII ('k', 'K', 's', 'S')
-// 3) asciiEqualFold, no special, but includes non-letters (including _)
-// 4) simpleLetterEqualFold, no specials, no non-letters.
-//
-// The letters S and K are special because they map to 3 runes, not just 2:
-//  * S maps to s and to U+017F 'ſ' Latin small letter long s
-//  * k maps to K and to U+212A 'K' Kelvin sign
-// See https://play.golang.org/p/tTxjOc0OGo
-//
-// The returned function is specialized for matching against s and
-// should only be given s. It's not curried for performance reasons.
-func foldFunc(s []byte) func(s, t []byte) bool {
-	nonLetter := false
-	special := false // special letter
-	for _, b := range s {
-		if b >= utf8.RuneSelf {
-			return bytes.EqualFold
-		}
-		upper := b & caseMask
-		if upper < 'A' || upper > 'Z' {
-			nonLetter = true
-		} else if upper == 'K' || upper == 'S' {
-			// See above for why these letters are special.
-			special = true
-		}
-	}
-	if special {
-		return equalFoldRight
-	}
-	if nonLetter {
-		return asciiEqualFold
-	}
-	return simpleLetterEqualFold
-}
-
-// equalFoldRight is a specialization of bytes.EqualFold when s is
-// known to be all ASCII (including punctuation), but contains an 's',
-// 'S', 'k', or 'K', requiring a Unicode fold on the bytes in t.
-// See comments on foldFunc.
-func equalFoldRight(s, t []byte) bool {
-	for _, sb := range s {
-		if len(t) == 0 {
-			return false
-		}
-		tb := t[0]
-		if tb < utf8.RuneSelf {
-			if sb != tb {
-				sbUpper := sb & caseMask
-				if 'A' <= sbUpper && sbUpper <= 'Z' {
-					if sbUpper != tb&caseMask {
-						return false
-					}
-				} else {
-					return false
-				}
-			}
-			t = t[1:]
-			continue
-		}
-		// sb is ASCII and t is not. t must be either kelvin
-		// sign or long s; sb must be s, S, k, or K.
-		tr, size := utf8.DecodeRune(t)
-		switch sb {
-		case 's', 'S':
-			if tr != smallLongEss {
-				return false
-			}
-		case 'k', 'K':
-			if tr != kelvin {
-				return false
-			}
-		default:
-			return false
-		}
-		t = t[size:]
-
-	}
-	if len(t) > 0 {
-		return false
-	}
-	return true
-}
-
-// asciiEqualFold is a specialization of bytes.EqualFold for use when
-// s is all ASCII (but may contain non-letters) and contains no
-// special-folding letters.
-// See comments on foldFunc.
-func asciiEqualFold(s, t []byte) bool {
-	if len(s) != len(t) {
-		return false
-	}
-	for i, sb := range s {
-		tb := t[i]
-		if sb == tb {
-			continue
-		}
-		if ('a' <= sb && sb <= 'z') || ('A' <= sb && sb <= 'Z') {
-			if sb&caseMask != tb&caseMask {
-				return false
-			}
-		} else {
-			return false
-		}
-	}
-	return true
-}
-
-// simpleLetterEqualFold is a specialization of bytes.EqualFold for
-// use when s is all ASCII letters (no underscores, etc) and also
-// doesn't contain 'k', 'K', 's', or 'S'.
-// See comments on foldFunc.
-func simpleLetterEqualFold(s, t []byte) bool {
-	if len(s) != len(t) {
-		return false
-	}
-	for i, b := range s {
-		if b&caseMask != t[i]&caseMask {
-			return false
-		}
-	}
-	return true
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/indent.go b/vendor/gopkg.in/mgo.v2/internal/json/indent.go
deleted file mode 100644
index fba1954..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/indent.go
+++ /dev/null
@@ -1,141 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import "bytes"
-
-// Compact appends to dst the JSON-encoded src with
-// insignificant space characters elided.
-func Compact(dst *bytes.Buffer, src []byte) error {
-	return compact(dst, src, false)
-}
-
-func compact(dst *bytes.Buffer, src []byte, escape bool) error {
-	origLen := dst.Len()
-	var scan scanner
-	scan.reset()
-	start := 0
-	for i, c := range src {
-		if escape && (c == '<' || c == '>' || c == '&') {
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			dst.WriteString(`\u00`)
-			dst.WriteByte(hex[c>>4])
-			dst.WriteByte(hex[c&0xF])
-			start = i + 1
-		}
-		// Convert U+2028 and U+2029 (E2 80 A8 and E2 80 A9).
-		if c == 0xE2 && i+2 < len(src) && src[i+1] == 0x80 && src[i+2]&^1 == 0xA8 {
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			dst.WriteString(`\u202`)
-			dst.WriteByte(hex[src[i+2]&0xF])
-			start = i + 3
-		}
-		v := scan.step(&scan, c)
-		if v >= scanSkipSpace {
-			if v == scanError {
-				break
-			}
-			if start < i {
-				dst.Write(src[start:i])
-			}
-			start = i + 1
-		}
-	}
-	if scan.eof() == scanError {
-		dst.Truncate(origLen)
-		return scan.err
-	}
-	if start < len(src) {
-		dst.Write(src[start:])
-	}
-	return nil
-}
-
-func newline(dst *bytes.Buffer, prefix, indent string, depth int) {
-	dst.WriteByte('\n')
-	dst.WriteString(prefix)
-	for i := 0; i < depth; i++ {
-		dst.WriteString(indent)
-	}
-}
-
-// Indent appends to dst an indented form of the JSON-encoded src.
-// Each element in a JSON object or array begins on a new,
-// indented line beginning with prefix followed by one or more
-// copies of indent according to the indentation nesting.
-// The data appended to dst does not begin with the prefix nor
-// any indentation, to make it easier to embed inside other formatted JSON data.
-// Although leading space characters (space, tab, carriage return, newline)
-// at the beginning of src are dropped, trailing space characters
-// at the end of src are preserved and copied to dst.
-// For example, if src has no trailing spaces, neither will dst;
-// if src ends in a trailing newline, so will dst.
-func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
-	origLen := dst.Len()
-	var scan scanner
-	scan.reset()
-	needIndent := false
-	depth := 0
-	for _, c := range src {
-		scan.bytes++
-		v := scan.step(&scan, c)
-		if v == scanSkipSpace {
-			continue
-		}
-		if v == scanError {
-			break
-		}
-		if needIndent && v != scanEndObject && v != scanEndArray {
-			needIndent = false
-			depth++
-			newline(dst, prefix, indent, depth)
-		}
-
-		// Emit semantically uninteresting bytes
-		// (in particular, punctuation in strings) unmodified.
-		if v == scanContinue {
-			dst.WriteByte(c)
-			continue
-		}
-
-		// Add spacing around real punctuation.
-		switch c {
-		case '{', '[':
-			// delay indent so that empty object and array are formatted as {} and [].
-			needIndent = true
-			dst.WriteByte(c)
-
-		case ',':
-			dst.WriteByte(c)
-			newline(dst, prefix, indent, depth)
-
-		case ':':
-			dst.WriteByte(c)
-			dst.WriteByte(' ')
-
-		case '}', ']':
-			if needIndent {
-				// suppress indent in empty object/array
-				needIndent = false
-			} else {
-				depth--
-				newline(dst, prefix, indent, depth)
-			}
-			dst.WriteByte(c)
-
-		default:
-			dst.WriteByte(c)
-		}
-	}
-	if scan.eof() == scanError {
-		dst.Truncate(origLen)
-		return scan.err
-	}
-	return nil
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/scanner.go b/vendor/gopkg.in/mgo.v2/internal/json/scanner.go
deleted file mode 100644
index 9708043..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/scanner.go
+++ /dev/null
@@ -1,697 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-// JSON value parser state machine.
-// Just about at the limit of what is reasonable to write by hand.
-// Some parts are a bit tedious, but overall it nicely factors out the
-// otherwise common code from the multiple scanning functions
-// in this package (Compact, Indent, checkValid, nextValue, etc).
-//
-// This file starts with two simple examples using the scanner
-// before diving into the scanner itself.
-
-import "strconv"
-
-// checkValid verifies that data is valid JSON-encoded data.
-// scan is passed in for use by checkValid to avoid an allocation.
-func checkValid(data []byte, scan *scanner) error {
-	scan.reset()
-	for _, c := range data {
-		scan.bytes++
-		if scan.step(scan, c) == scanError {
-			return scan.err
-		}
-	}
-	if scan.eof() == scanError {
-		return scan.err
-	}
-	return nil
-}
-
-// nextValue splits data after the next whole JSON value,
-// returning that value and the bytes that follow it as separate slices.
-// scan is passed in for use by nextValue to avoid an allocation.
-func nextValue(data []byte, scan *scanner) (value, rest []byte, err error) {
-	scan.reset()
-	for i, c := range data {
-		v := scan.step(scan, c)
-		if v >= scanEndObject {
-			switch v {
-			// probe the scanner with a space to determine whether we will
-			// get scanEnd on the next character. Otherwise, if the next character
-			// is not a space, scanEndTop allocates a needless error.
-			case scanEndObject, scanEndArray, scanEndParams:
-				if scan.step(scan, ' ') == scanEnd {
-					return data[:i+1], data[i+1:], nil
-				}
-			case scanError:
-				return nil, nil, scan.err
-			case scanEnd:
-				return data[:i], data[i:], nil
-			}
-		}
-	}
-	if scan.eof() == scanError {
-		return nil, nil, scan.err
-	}
-	return data, nil, nil
-}
-
-// A SyntaxError is a description of a JSON syntax error.
-type SyntaxError struct {
-	msg    string // description of error
-	Offset int64  // error occurred after reading Offset bytes
-}
-
-func (e *SyntaxError) Error() string { return e.msg }
-
-// A scanner is a JSON scanning state machine.
-// Callers call scan.reset() and then pass bytes in one at a time
-// by calling scan.step(&scan, c) for each byte.
-// The return value, referred to as an opcode, tells the
-// caller about significant parsing events like beginning
-// and ending literals, objects, and arrays, so that the
-// caller can follow along if it wishes.
-// The return value scanEnd indicates that a single top-level
-// JSON value has been completed, *before* the byte that
-// just got passed in.  (The indication must be delayed in order
-// to recognize the end of numbers: is 123 a whole value or
-// the beginning of 12345e+6?).
-type scanner struct {
-	// The step is a func to be called to execute the next transition.
-	// Also tried using an integer constant and a single func
-	// with a switch, but using the func directly was 10% faster
-	// on a 64-bit Mac Mini, and it's nicer to read.
-	step func(*scanner, byte) int
-
-	// Reached end of top-level value.
-	endTop bool
-
-	// Stack of what we're in the middle of - array values, object keys, object values.
-	parseState []int
-
-	// Error that happened, if any.
-	err error
-
-	// 1-byte redo (see undo method)
-	redo      bool
-	redoCode  int
-	redoState func(*scanner, byte) int
-
-	// total bytes consumed, updated by decoder.Decode
-	bytes int64
-}
-
-// These values are returned by the state transition functions
-// assigned to scanner.state and the method scanner.eof.
-// They give details about the current state of the scan that
-// callers might be interested to know about.
-// It is okay to ignore the return value of any particular
-// call to scanner.state: if one call returns scanError,
-// every subsequent call will return scanError too.
-const (
-	// Continue.
-	scanContinue     = iota // uninteresting byte
-	scanBeginLiteral        // end implied by next result != scanContinue
-	scanBeginObject         // begin object
-	scanObjectKey           // just finished object key (string)
-	scanObjectValue         // just finished non-last object value
-	scanEndObject           // end object (implies scanObjectValue if possible)
-	scanBeginArray          // begin array
-	scanArrayValue          // just finished array value
-	scanEndArray            // end array (implies scanArrayValue if possible)
-	scanBeginName           // begin function call
-	scanParam               // begin function argument
-	scanEndParams           // end function call
-	scanSkipSpace           // space byte; can skip; known to be last "continue" result
-
-	// Stop.
-	scanEnd   // top-level value ended *before* this byte; known to be first "stop" result
-	scanError // hit an error, scanner.err.
-)
-
-// These values are stored in the parseState stack.
-// They give the current state of a composite value
-// being scanned. If the parser is inside a nested value
-// the parseState describes the nested state, outermost at entry 0.
-const (
-	parseObjectKey   = iota // parsing object key (before colon)
-	parseObjectValue        // parsing object value (after colon)
-	parseArrayValue         // parsing array value
-	parseName               // parsing unquoted name
-	parseParam              // parsing function argument value
-)
-
-// reset prepares the scanner for use.
-// It must be called before calling s.step.
-func (s *scanner) reset() {
-	s.step = stateBeginValue
-	s.parseState = s.parseState[0:0]
-	s.err = nil
-	s.redo = false
-	s.endTop = false
-}
-
-// eof tells the scanner that the end of input has been reached.
-// It returns a scan status just as s.step does.
-func (s *scanner) eof() int {
-	if s.err != nil {
-		return scanError
-	}
-	if s.endTop {
-		return scanEnd
-	}
-	s.step(s, ' ')
-	if s.endTop {
-		return scanEnd
-	}
-	if s.err == nil {
-		s.err = &SyntaxError{"unexpected end of JSON input", s.bytes}
-	}
-	return scanError
-}
-
-// pushParseState pushes a new parse state p onto the parse stack.
-func (s *scanner) pushParseState(p int) {
-	s.parseState = append(s.parseState, p)
-}
-
-// popParseState pops a parse state (already obtained) off the stack
-// and updates s.step accordingly.
-func (s *scanner) popParseState() {
-	n := len(s.parseState) - 1
-	s.parseState = s.parseState[0:n]
-	s.redo = false
-	if n == 0 {
-		s.step = stateEndTop
-		s.endTop = true
-	} else {
-		s.step = stateEndValue
-	}
-}
-
-func isSpace(c byte) bool {
-	return c == ' ' || c == '\t' || c == '\r' || c == '\n'
-}
-
-// stateBeginValueOrEmpty is the state after reading `[`.
-func stateBeginValueOrEmpty(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
-		return scanSkipSpace
-	}
-	if c == ']' {
-		return stateEndValue(s, c)
-	}
-	return stateBeginValue(s, c)
-}
-
-// stateBeginValue is the state at the beginning of the input.
-func stateBeginValue(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
-		return scanSkipSpace
-	}
-	switch c {
-	case '{':
-		s.step = stateBeginStringOrEmpty
-		s.pushParseState(parseObjectKey)
-		return scanBeginObject
-	case '[':
-		s.step = stateBeginValueOrEmpty
-		s.pushParseState(parseArrayValue)
-		return scanBeginArray
-	case '"':
-		s.step = stateInString
-		return scanBeginLiteral
-	case '-':
-		s.step = stateNeg
-		return scanBeginLiteral
-	case '0': // beginning of 0.123
-		s.step = state0
-		return scanBeginLiteral
-	case 'n':
-		s.step = stateNew0
-		return scanBeginName
-	}
-	if '1' <= c && c <= '9' { // beginning of 1234.5
-		s.step = state1
-		return scanBeginLiteral
-	}
-	if isName(c) {
-		s.step = stateName
-		return scanBeginName
-	}
-	return s.error(c, "looking for beginning of value")
-}
-
-func isName(c byte) bool {
-	return c == '$' || c == '_' || 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || '0' <= c && c <= '9'
-}
-
-// stateBeginStringOrEmpty is the state after reading `{`.
-func stateBeginStringOrEmpty(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
-		return scanSkipSpace
-	}
-	if c == '}' {
-		n := len(s.parseState)
-		s.parseState[n-1] = parseObjectValue
-		return stateEndValue(s, c)
-	}
-	return stateBeginString(s, c)
-}
-
-// stateBeginString is the state after reading `{"key": value,`.
-func stateBeginString(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
-		return scanSkipSpace
-	}
-	if c == '"' {
-		s.step = stateInString
-		return scanBeginLiteral
-	}
-	if isName(c) {
-		s.step = stateName
-		return scanBeginName
-	}
-	return s.error(c, "looking for beginning of object key string")
-}
-
-// stateEndValue is the state after completing a value,
-// such as after reading `{}` or `true` or `["x"`.
-func stateEndValue(s *scanner, c byte) int {
-	n := len(s.parseState)
-	if n == 0 {
-		// Completed top-level before the current byte.
-		s.step = stateEndTop
-		s.endTop = true
-		return stateEndTop(s, c)
-	}
-	if c <= ' ' && isSpace(c) {
-		s.step = stateEndValue
-		return scanSkipSpace
-	}
-	ps := s.parseState[n-1]
-	switch ps {
-	case parseObjectKey:
-		if c == ':' {
-			s.parseState[n-1] = parseObjectValue
-			s.step = stateBeginValue
-			return scanObjectKey
-		}
-		return s.error(c, "after object key")
-	case parseObjectValue:
-		if c == ',' {
-			s.parseState[n-1] = parseObjectKey
-			s.step = stateBeginStringOrEmpty
-			return scanObjectValue
-		}
-		if c == '}' {
-			s.popParseState()
-			return scanEndObject
-		}
-		return s.error(c, "after object key:value pair")
-	case parseArrayValue:
-		if c == ',' {
-			s.step = stateBeginValueOrEmpty
-			return scanArrayValue
-		}
-		if c == ']' {
-			s.popParseState()
-			return scanEndArray
-		}
-		return s.error(c, "after array element")
-	case parseParam:
-		if c == ',' {
-			s.step = stateBeginValue
-			return scanParam
-		}
-		if c == ')' {
-			s.popParseState()
-			return scanEndParams
-		}
-		return s.error(c, "after array element")
-	}
-	return s.error(c, "")
-}
-
-// stateEndTop is the state after finishing the top-level value,
-// such as after reading `{}` or `[1,2,3]`.
-// Only space characters should be seen now.
-func stateEndTop(s *scanner, c byte) int {
-	if c != ' ' && c != '\t' && c != '\r' && c != '\n' {
-		// Complain about non-space byte on next call.
-		s.error(c, "after top-level value")
-	}
-	return scanEnd
-}
-
-// stateInString is the state after reading `"`.
-func stateInString(s *scanner, c byte) int {
-	if c == '"' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	if c == '\\' {
-		s.step = stateInStringEsc
-		return scanContinue
-	}
-	if c < 0x20 {
-		return s.error(c, "in string literal")
-	}
-	return scanContinue
-}
-
-// stateInStringEsc is the state after reading `"\` during a quoted string.
-func stateInStringEsc(s *scanner, c byte) int {
-	switch c {
-	case 'b', 'f', 'n', 'r', 't', '\\', '/', '"':
-		s.step = stateInString
-		return scanContinue
-	case 'u':
-		s.step = stateInStringEscU
-		return scanContinue
-	}
-	return s.error(c, "in string escape code")
-}
-
-// stateInStringEscU is the state after reading `"\u` during a quoted string.
-func stateInStringEscU(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInStringEscU1
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateInStringEscU1 is the state after reading `"\u1` during a quoted string.
-func stateInStringEscU1(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInStringEscU12
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateInStringEscU12 is the state after reading `"\u12` during a quoted string.
-func stateInStringEscU12(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInStringEscU123
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateInStringEscU123 is the state after reading `"\u123` during a quoted string.
-func stateInStringEscU123(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' || 'a' <= c && c <= 'f' || 'A' <= c && c <= 'F' {
-		s.step = stateInString
-		return scanContinue
-	}
-	// numbers
-	return s.error(c, "in \\u hexadecimal character escape")
-}
-
-// stateNeg is the state after reading `-` during a number.
-func stateNeg(s *scanner, c byte) int {
-	if c == '0' {
-		s.step = state0
-		return scanContinue
-	}
-	if '1' <= c && c <= '9' {
-		s.step = state1
-		return scanContinue
-	}
-	return s.error(c, "in numeric literal")
-}
-
-// state1 is the state after reading a non-zero integer during a number,
-// such as after reading `1` or `100` but not `0`.
-func state1(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		s.step = state1
-		return scanContinue
-	}
-	return state0(s, c)
-}
-
-// state0 is the state after reading `0` during a number.
-func state0(s *scanner, c byte) int {
-	if c == '.' {
-		s.step = stateDot
-		return scanContinue
-	}
-	if c == 'e' || c == 'E' {
-		s.step = stateE
-		return scanContinue
-	}
-	return stateEndValue(s, c)
-}
-
-// stateDot is the state after reading the integer and decimal point in a number,
-// such as after reading `1.`.
-func stateDot(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		s.step = stateDot0
-		return scanContinue
-	}
-	return s.error(c, "after decimal point in numeric literal")
-}
-
-// stateDot0 is the state after reading the integer, decimal point, and subsequent
-// digits of a number, such as after reading `3.14`.
-func stateDot0(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		return scanContinue
-	}
-	if c == 'e' || c == 'E' {
-		s.step = stateE
-		return scanContinue
-	}
-	return stateEndValue(s, c)
-}
-
-// stateE is the state after reading the mantissa and e in a number,
-// such as after reading `314e` or `0.314e`.
-func stateE(s *scanner, c byte) int {
-	if c == '+' || c == '-' {
-		s.step = stateESign
-		return scanContinue
-	}
-	return stateESign(s, c)
-}
-
-// stateESign is the state after reading the mantissa, e, and sign in a number,
-// such as after reading `314e-` or `0.314e+`.
-func stateESign(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		s.step = stateE0
-		return scanContinue
-	}
-	return s.error(c, "in exponent of numeric literal")
-}
-
-// stateE0 is the state after reading the mantissa, e, optional sign,
-// and at least one digit of the exponent in a number,
-// such as after reading `314e-2` or `0.314e+1` or `3.14e0`.
-func stateE0(s *scanner, c byte) int {
-	if '0' <= c && c <= '9' {
-		return scanContinue
-	}
-	return stateEndValue(s, c)
-}
-
-// stateNew0 is the state after reading `n`.
-func stateNew0(s *scanner, c byte) int {
-	if c == 'e' {
-		s.step = stateNew1
-		return scanContinue
-	}
-	s.step = stateName
-	return stateName(s, c)
-}
-
-// stateNew1 is the state after reading `ne`.
-func stateNew1(s *scanner, c byte) int {
-	if c == 'w' {
-		s.step = stateNew2
-		return scanContinue
-	}
-	s.step = stateName
-	return stateName(s, c)
-}
-
-// stateNew2 is the state after reading `new`.
-func stateNew2(s *scanner, c byte) int {
-	s.step = stateName
-	if c == ' ' {
-		return scanContinue
-	}
-	return stateName(s, c)
-}
-
-// stateName is the state while reading an unquoted function name.
-func stateName(s *scanner, c byte) int {
-	if isName(c) {
-		return scanContinue
-	}
-	if c == '(' {
-		s.step = stateParamOrEmpty
-		s.pushParseState(parseParam)
-		return scanParam
-	}
-	return stateEndValue(s, c)
-}
-
-// stateParamOrEmpty is the state after reading `(`.
-func stateParamOrEmpty(s *scanner, c byte) int {
-	if c <= ' ' && isSpace(c) {
-		return scanSkipSpace
-	}
-	if c == ')' {
-		return stateEndValue(s, c)
-	}
-	return stateBeginValue(s, c)
-}
-
-// stateT is the state after reading `t`.
-func stateT(s *scanner, c byte) int {
-	if c == 'r' {
-		s.step = stateTr
-		return scanContinue
-	}
-	return s.error(c, "in literal true (expecting 'r')")
-}
-
-// stateTr is the state after reading `tr`.
-func stateTr(s *scanner, c byte) int {
-	if c == 'u' {
-		s.step = stateTru
-		return scanContinue
-	}
-	return s.error(c, "in literal true (expecting 'u')")
-}
-
-// stateTru is the state after reading `tru`.
-func stateTru(s *scanner, c byte) int {
-	if c == 'e' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	return s.error(c, "in literal true (expecting 'e')")
-}
-
-// stateF is the state after reading `f`.
-func stateF(s *scanner, c byte) int {
-	if c == 'a' {
-		s.step = stateFa
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 'a')")
-}
-
-// stateFa is the state after reading `fa`.
-func stateFa(s *scanner, c byte) int {
-	if c == 'l' {
-		s.step = stateFal
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 'l')")
-}
-
-// stateFal is the state after reading `fal`.
-func stateFal(s *scanner, c byte) int {
-	if c == 's' {
-		s.step = stateFals
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 's')")
-}
-
-// stateFals is the state after reading `fals`.
-func stateFals(s *scanner, c byte) int {
-	if c == 'e' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	return s.error(c, "in literal false (expecting 'e')")
-}
-
-// stateN is the state after reading `n`.
-func stateN(s *scanner, c byte) int {
-	if c == 'u' {
-		s.step = stateNu
-		return scanContinue
-	}
-	return s.error(c, "in literal null (expecting 'u')")
-}
-
-// stateNu is the state after reading `nu`.
-func stateNu(s *scanner, c byte) int {
-	if c == 'l' {
-		s.step = stateNul
-		return scanContinue
-	}
-	return s.error(c, "in literal null (expecting 'l')")
-}
-
-// stateNul is the state after reading `nul`.
-func stateNul(s *scanner, c byte) int {
-	if c == 'l' {
-		s.step = stateEndValue
-		return scanContinue
-	}
-	return s.error(c, "in literal null (expecting 'l')")
-}
-
-// stateError is the state after reaching a syntax error,
-// such as after reading `[1}` or `5.1.2`.
-func stateError(s *scanner, c byte) int {
-	return scanError
-}
-
-// error records an error and switches to the error state.
-func (s *scanner) error(c byte, context string) int {
-	s.step = stateError
-	s.err = &SyntaxError{"invalid character " + quoteChar(c) + " " + context, s.bytes}
-	return scanError
-}
-
-// quoteChar formats c as a quoted character literal
-func quoteChar(c byte) string {
-	// special cases - different from quoted strings
-	if c == '\'' {
-		return `'\''`
-	}
-	if c == '"' {
-		return `'"'`
-	}
-
-	// use quoted string with different quotation marks
-	s := strconv.Quote(string(c))
-	return "'" + s[1:len(s)-1] + "'"
-}
-
-// undo causes the scanner to return scanCode from the next state transition.
-// This gives callers a simple 1-byte undo mechanism.
-func (s *scanner) undo(scanCode int) {
-	if s.redo {
-		panic("json: invalid use of scanner")
-	}
-	s.redoCode = scanCode
-	s.redoState = s.step
-	s.step = stateRedo
-	s.redo = true
-}
-
-// stateRedo helps implement the scanner's 1-byte undo.
-func stateRedo(s *scanner, c byte) int {
-	s.redo = false
-	s.step = s.redoState
-	return s.redoCode
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/stream.go b/vendor/gopkg.in/mgo.v2/internal/json/stream.go
deleted file mode 100644
index e023702..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/stream.go
+++ /dev/null
@@ -1,510 +0,0 @@
-// Copyright 2010 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import (
-	"bytes"
-	"errors"
-	"io"
-)
-
-// A Decoder reads and decodes JSON values from an input stream.
-type Decoder struct {
-	r     io.Reader
-	buf   []byte
-	d     decodeState
-	scanp int // start of unread data in buf
-	scan  scanner
-	err   error
-
-	tokenState int
-	tokenStack []int
-}
-
-// NewDecoder returns a new decoder that reads from r.
-//
-// The decoder introduces its own buffering and may
-// read data from r beyond the JSON values requested.
-func NewDecoder(r io.Reader) *Decoder {
-	return &Decoder{r: r}
-}
-
-// UseNumber causes the Decoder to unmarshal a number into an interface{} as a
-// Number instead of as a float64.
-func (dec *Decoder) UseNumber() { dec.d.useNumber = true }
-
-// Decode reads the next JSON-encoded value from its
-// input and stores it in the value pointed to by v.
-//
-// See the documentation for Unmarshal for details about
-// the conversion of JSON into a Go value.
-func (dec *Decoder) Decode(v interface{}) error {
-	if dec.err != nil {
-		return dec.err
-	}
-
-	if err := dec.tokenPrepareForDecode(); err != nil {
-		return err
-	}
-
-	if !dec.tokenValueAllowed() {
-		return &SyntaxError{msg: "not at beginning of value"}
-	}
-
-	// Read whole value into buffer.
-	n, err := dec.readValue()
-	if err != nil {
-		return err
-	}
-	dec.d.init(dec.buf[dec.scanp : dec.scanp+n])
-	dec.scanp += n
-
-	// Don't save err from unmarshal into dec.err:
-	// the connection is still usable since we read a complete JSON
-	// object from it before the error happened.
-	err = dec.d.unmarshal(v)
-
-	// fixup token streaming state
-	dec.tokenValueEnd()
-
-	return err
-}
-
-// Buffered returns a reader of the data remaining in the Decoder's
-// buffer. The reader is valid until the next call to Decode.
-func (dec *Decoder) Buffered() io.Reader {
-	return bytes.NewReader(dec.buf[dec.scanp:])
-}
-
-// readValue reads a JSON value into dec.buf.
-// It returns the length of the encoding.
-func (dec *Decoder) readValue() (int, error) {
-	dec.scan.reset()
-
-	scanp := dec.scanp
-	var err error
-Input:
-	for {
-		// Look in the buffer for a new value.
-		for i, c := range dec.buf[scanp:] {
-			dec.scan.bytes++
-			v := dec.scan.step(&dec.scan, c)
-			if v == scanEnd {
-				scanp += i
-				break Input
-			}
-			// scanEnd is delayed one byte.
-			// We might block trying to get that byte from src,
-			// so instead invent a space byte.
-			if (v == scanEndObject || v == scanEndArray) && dec.scan.step(&dec.scan, ' ') == scanEnd {
-				scanp += i + 1
-				break Input
-			}
-			if v == scanError {
-				dec.err = dec.scan.err
-				return 0, dec.scan.err
-			}
-		}
-		scanp = len(dec.buf)
-
-		// Did the last read have an error?
-		// Delayed until now to allow buffer scan.
-		if err != nil {
-			if err == io.EOF {
-				if dec.scan.step(&dec.scan, ' ') == scanEnd {
-					break Input
-				}
-				if nonSpace(dec.buf) {
-					err = io.ErrUnexpectedEOF
-				}
-			}
-			dec.err = err
-			return 0, err
-		}
-
-		n := scanp - dec.scanp
-		err = dec.refill()
-		scanp = dec.scanp + n
-	}
-	return scanp - dec.scanp, nil
-}
-
-func (dec *Decoder) refill() error {
-	// Make room to read more into the buffer.
-	// First slide down data already consumed.
-	if dec.scanp > 0 {
-		n := copy(dec.buf, dec.buf[dec.scanp:])
-		dec.buf = dec.buf[:n]
-		dec.scanp = 0
-	}
-
-	// Grow buffer if not large enough.
-	const minRead = 512
-	if cap(dec.buf)-len(dec.buf) < minRead {
-		newBuf := make([]byte, len(dec.buf), 2*cap(dec.buf)+minRead)
-		copy(newBuf, dec.buf)
-		dec.buf = newBuf
-	}
-
-	// Read. Delay error for next iteration (after scan).
-	n, err := dec.r.Read(dec.buf[len(dec.buf):cap(dec.buf)])
-	dec.buf = dec.buf[0 : len(dec.buf)+n]
-
-	return err
-}
-
-func nonSpace(b []byte) bool {
-	for _, c := range b {
-		if !isSpace(c) {
-			return true
-		}
-	}
-	return false
-}
-
-// An Encoder writes JSON values to an output stream.
-type Encoder struct {
-	w          io.Writer
-	err        error
-	escapeHTML bool
-
-	indentBuf    *bytes.Buffer
-	indentPrefix string
-	indentValue  string
-
-	ext Extension
-}
-
-// NewEncoder returns a new encoder that writes to w.
-func NewEncoder(w io.Writer) *Encoder {
-	return &Encoder{w: w, escapeHTML: true}
-}
-
-// Encode writes the JSON encoding of v to the stream,
-// followed by a newline character.
-//
-// See the documentation for Marshal for details about the
-// conversion of Go values to JSON.
-func (enc *Encoder) Encode(v interface{}) error {
-	if enc.err != nil {
-		return enc.err
-	}
-	e := newEncodeState()
-	e.ext = enc.ext
-	err := e.marshal(v, encOpts{escapeHTML: enc.escapeHTML})
-	if err != nil {
-		return err
-	}
-
-	// Terminate each value with a newline.
-	// This makes the output look a little nicer
-	// when debugging, and some kind of space
-	// is required if the encoded value was a number,
-	// so that the reader knows there aren't more
-	// digits coming.
-	e.WriteByte('\n')
-
-	b := e.Bytes()
-	if enc.indentBuf != nil {
-		enc.indentBuf.Reset()
-		err = Indent(enc.indentBuf, b, enc.indentPrefix, enc.indentValue)
-		if err != nil {
-			return err
-		}
-		b = enc.indentBuf.Bytes()
-	}
-	if _, err = enc.w.Write(b); err != nil {
-		enc.err = err
-	}
-	encodeStatePool.Put(e)
-	return err
-}
-
-// Indent sets the encoder to format each encoded value with Indent.
-func (enc *Encoder) Indent(prefix, indent string) {
-	enc.indentBuf = new(bytes.Buffer)
-	enc.indentPrefix = prefix
-	enc.indentValue = indent
-}
-
-// DisableHTMLEscaping causes the encoder not to escape angle brackets
-// ("<" and ">") or ampersands ("&") in JSON strings.
-func (enc *Encoder) DisableHTMLEscaping() {
-	enc.escapeHTML = false
-}
-
-// RawMessage is a raw encoded JSON value.
-// It implements Marshaler and Unmarshaler and can
-// be used to delay JSON decoding or precompute a JSON encoding.
-type RawMessage []byte
-
-// MarshalJSON returns *m as the JSON encoding of m.
-func (m *RawMessage) MarshalJSON() ([]byte, error) {
-	return *m, nil
-}
-
-// UnmarshalJSON sets *m to a copy of data.
-func (m *RawMessage) UnmarshalJSON(data []byte) error {
-	if m == nil {
-		return errors.New("json.RawMessage: UnmarshalJSON on nil pointer")
-	}
-	*m = append((*m)[0:0], data...)
-	return nil
-}
-
-var _ Marshaler = (*RawMessage)(nil)
-var _ Unmarshaler = (*RawMessage)(nil)
-
-// A Token holds a value of one of these types:
-//
-//	Delim, for the four JSON delimiters [ ] { }
-//	bool, for JSON booleans
-//	float64, for JSON numbers
-//	Number, for JSON numbers
-//	string, for JSON string literals
-//	nil, for JSON null
-//
-type Token interface{}
-
-const (
-	tokenTopValue = iota
-	tokenArrayStart
-	tokenArrayValue
-	tokenArrayComma
-	tokenObjectStart
-	tokenObjectKey
-	tokenObjectColon
-	tokenObjectValue
-	tokenObjectComma
-)
-
-// advance tokenstate from a separator state to a value state
-func (dec *Decoder) tokenPrepareForDecode() error {
-	// Note: Not calling peek before switch, to avoid
-	// putting peek into the standard Decode path.
-	// peek is only called when using the Token API.
-	switch dec.tokenState {
-	case tokenArrayComma:
-		c, err := dec.peek()
-		if err != nil {
-			return err
-		}
-		if c != ',' {
-			return &SyntaxError{"expected comma after array element", 0}
-		}
-		dec.scanp++
-		dec.tokenState = tokenArrayValue
-	case tokenObjectColon:
-		c, err := dec.peek()
-		if err != nil {
-			return err
-		}
-		if c != ':' {
-			return &SyntaxError{"expected colon after object key", 0}
-		}
-		dec.scanp++
-		dec.tokenState = tokenObjectValue
-	}
-	return nil
-}
-
-func (dec *Decoder) tokenValueAllowed() bool {
-	switch dec.tokenState {
-	case tokenTopValue, tokenArrayStart, tokenArrayValue, tokenObjectValue:
-		return true
-	}
-	return false
-}
-
-func (dec *Decoder) tokenValueEnd() {
-	switch dec.tokenState {
-	case tokenArrayStart, tokenArrayValue:
-		dec.tokenState = tokenArrayComma
-	case tokenObjectValue:
-		dec.tokenState = tokenObjectComma
-	}
-}
-
-// A Delim is a JSON array or object delimiter, one of [ ] { or }.
-type Delim rune
-
-func (d Delim) String() string {
-	return string(d)
-}
-
-// Token returns the next JSON token in the input stream.
-// At the end of the input stream, Token returns nil, io.EOF.
-//
-// Token guarantees that the delimiters [ ] { } it returns are
-// properly nested and matched: if Token encounters an unexpected
-// delimiter in the input, it will return an error.
-//
-// The input stream consists of basic JSON values—bool, string,
-// number, and null—along with delimiters [ ] { } of type Delim
-// to mark the start and end of arrays and objects.
-// Commas and colons are elided.
-func (dec *Decoder) Token() (Token, error) {
-	for {
-		c, err := dec.peek()
-		if err != nil {
-			return nil, err
-		}
-		switch c {
-		case '[':
-			if !dec.tokenValueAllowed() {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
-			dec.tokenState = tokenArrayStart
-			return Delim('['), nil
-
-		case ']':
-			if dec.tokenState != tokenArrayStart && dec.tokenState != tokenArrayComma {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
-			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
-			dec.tokenValueEnd()
-			return Delim(']'), nil
-
-		case '{':
-			if !dec.tokenValueAllowed() {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenStack = append(dec.tokenStack, dec.tokenState)
-			dec.tokenState = tokenObjectStart
-			return Delim('{'), nil
-
-		case '}':
-			if dec.tokenState != tokenObjectStart && dec.tokenState != tokenObjectComma {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenState = dec.tokenStack[len(dec.tokenStack)-1]
-			dec.tokenStack = dec.tokenStack[:len(dec.tokenStack)-1]
-			dec.tokenValueEnd()
-			return Delim('}'), nil
-
-		case ':':
-			if dec.tokenState != tokenObjectColon {
-				return dec.tokenError(c)
-			}
-			dec.scanp++
-			dec.tokenState = tokenObjectValue
-			continue
-
-		case ',':
-			if dec.tokenState == tokenArrayComma {
-				dec.scanp++
-				dec.tokenState = tokenArrayValue
-				continue
-			}
-			if dec.tokenState == tokenObjectComma {
-				dec.scanp++
-				dec.tokenState = tokenObjectKey
-				continue
-			}
-			return dec.tokenError(c)
-
-		case '"':
-			if dec.tokenState == tokenObjectStart || dec.tokenState == tokenObjectKey {
-				var x string
-				old := dec.tokenState
-				dec.tokenState = tokenTopValue
-				err := dec.Decode(&x)
-				dec.tokenState = old
-				if err != nil {
-					clearOffset(err)
-					return nil, err
-				}
-				dec.tokenState = tokenObjectColon
-				return x, nil
-			}
-			fallthrough
-
-		default:
-			if !dec.tokenValueAllowed() {
-				return dec.tokenError(c)
-			}
-			var x interface{}
-			if err := dec.Decode(&x); err != nil {
-				clearOffset(err)
-				return nil, err
-			}
-			return x, nil
-		}
-	}
-}
-
-func clearOffset(err error) {
-	if s, ok := err.(*SyntaxError); ok {
-		s.Offset = 0
-	}
-}
-
-func (dec *Decoder) tokenError(c byte) (Token, error) {
-	var context string
-	switch dec.tokenState {
-	case tokenTopValue:
-		context = " looking for beginning of value"
-	case tokenArrayStart, tokenArrayValue, tokenObjectValue:
-		context = " looking for beginning of value"
-	case tokenArrayComma:
-		context = " after array element"
-	case tokenObjectKey:
-		context = " looking for beginning of object key string"
-	case tokenObjectColon:
-		context = " after object key"
-	case tokenObjectComma:
-		context = " after object key:value pair"
-	}
-	return nil, &SyntaxError{"invalid character " + quoteChar(c) + " " + context, 0}
-}
-
-// More reports whether there is another element in the
-// current array or object being parsed.
-func (dec *Decoder) More() bool {
-	c, err := dec.peek()
-	return err == nil && c != ']' && c != '}'
-}
-
-func (dec *Decoder) peek() (byte, error) {
-	var err error
-	for {
-		for i := dec.scanp; i < len(dec.buf); i++ {
-			c := dec.buf[i]
-			if isSpace(c) {
-				continue
-			}
-			dec.scanp = i
-			return c, nil
-		}
-		// buffer has been scanned, now report any error
-		if err != nil {
-			return 0, err
-		}
-		err = dec.refill()
-	}
-}
-
-/*
-TODO
-
-// EncodeToken writes the given JSON token to the stream.
-// It returns an error if the delimiters [ ] { } are not properly used.
-//
-// EncodeToken does not call Flush, because usually it is part of
-// a larger operation such as Encode, and those will call Flush when finished.
-// Callers that create an Encoder and then invoke EncodeToken directly,
-// without using Encode, need to call Flush when finished to ensure that
-// the JSON is written to the underlying writer.
-func (e *Encoder) EncodeToken(t Token) error  {
-	...
-}
-
-*/
diff --git a/vendor/gopkg.in/mgo.v2/internal/json/tags.go b/vendor/gopkg.in/mgo.v2/internal/json/tags.go
deleted file mode 100644
index c38fd51..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/json/tags.go
+++ /dev/null
@@ -1,44 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package json
-
-import (
-	"strings"
-)
-
-// tagOptions is the string following a comma in a struct field's "json"
-// tag, or the empty string. It does not include the leading comma.
-type tagOptions string
-
-// parseTag splits a struct field's json tag into its name and
-// comma-separated options.
-func parseTag(tag string) (string, tagOptions) {
-	if idx := strings.Index(tag, ","); idx != -1 {
-		return tag[:idx], tagOptions(tag[idx+1:])
-	}
-	return tag, tagOptions("")
-}
-
-// Contains reports whether a comma-separated list of options
-// contains a particular substr flag. substr must be surrounded by a
-// string boundary or commas.
-func (o tagOptions) Contains(optionName string) bool {
-	if len(o) == 0 {
-		return false
-	}
-	s := string(o)
-	for s != "" {
-		var next string
-		i := strings.Index(s, ",")
-		if i >= 0 {
-			s, next = s[:i], s[i+1:]
-		}
-		if s == optionName {
-			return true
-		}
-		s = next
-	}
-	return false
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl.c b/vendor/gopkg.in/mgo.v2/internal/sasl/sasl.c
deleted file mode 100644
index 8be0bc4..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl.c
+++ /dev/null
@@ -1,77 +0,0 @@
-// +build !windows
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-#include <sasl/sasl.h>
-
-static int mgo_sasl_simple(void *context, int id, const char **result, unsigned int *len)
-{
-	if (!result) {
-		return SASL_BADPARAM;
-	}
-	switch (id) {
-	case SASL_CB_USER:
-		*result = (char *)context;
-		break;
-	case SASL_CB_AUTHNAME:
-		*result = (char *)context;
-		break;
-	case SASL_CB_LANGUAGE:
-		*result = NULL;
-		break;
-	default:
-		return SASL_BADPARAM;
-	}
-	if (len) {
-		*len = *result ? strlen(*result) : 0;
-	}
-	return SASL_OK;
-}
-
-typedef int (*callback)(void);
-
-static int mgo_sasl_secret(sasl_conn_t *conn, void *context, int id, sasl_secret_t **result)
-{
-	if (!conn || !result || id != SASL_CB_PASS) {
-		return SASL_BADPARAM;
-	}
-	*result = (sasl_secret_t *)context;
-	return SASL_OK;
-}
-
-sasl_callback_t *mgo_sasl_callbacks(const char *username, const char *password)
-{
-	sasl_callback_t *cb = malloc(4 * sizeof(sasl_callback_t));
-	int n = 0;
-
-	size_t len = strlen(password);
-	sasl_secret_t *secret = (sasl_secret_t*)malloc(sizeof(sasl_secret_t) + len);
-	if (!secret) {
-		free(cb);
-		return NULL;
-	}
-	strcpy((char *)secret->data, password);
-	secret->len = len;
-
-	cb[n].id = SASL_CB_PASS;
-	cb[n].proc = (callback)&mgo_sasl_secret;
-	cb[n].context = secret;
-	n++;
-
-	cb[n].id = SASL_CB_USER;
-	cb[n].proc = (callback)&mgo_sasl_simple;
-	cb[n].context = (char*)username;
-	n++;
-
-	cb[n].id = SASL_CB_AUTHNAME;
-	cb[n].proc = (callback)&mgo_sasl_simple;
-	cb[n].context = (char*)username;
-	n++;
-
-	cb[n].id = SASL_CB_LIST_END;
-	cb[n].proc = NULL;
-	cb[n].context = NULL;
-
-	return cb;
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl.go b/vendor/gopkg.in/mgo.v2/internal/sasl/sasl.go
deleted file mode 100644
index 8375ddd..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl.go
+++ /dev/null
@@ -1,138 +0,0 @@
-// Package sasl is an implementation detail of the mgo package.
-//
-// This package is not meant to be used by itself.
-//
-
-// +build !windows
-
-package sasl
-
-// #cgo LDFLAGS: -lsasl2
-//
-// struct sasl_conn {};
-//
-// #include <stdlib.h>
-// #include <sasl/sasl.h>
-//
-// sasl_callback_t *mgo_sasl_callbacks(const char *username, const char *password);
-//
-import "C"
-
-import (
-	"fmt"
-	"strings"
-	"sync"
-	"unsafe"
-)
-
-type saslStepper interface {
-	Step(serverData []byte) (clientData []byte, done bool, err error)
-	Close()
-}
-
-type saslSession struct {
-	conn *C.sasl_conn_t
-	step int
-	mech string
-
-	cstrings  []*C.char
-	callbacks *C.sasl_callback_t
-}
-
-var initError error
-var initOnce sync.Once
-
-func initSASL() {
-	rc := C.sasl_client_init(nil)
-	if rc != C.SASL_OK {
-		initError = saslError(rc, nil, "cannot initialize SASL library")
-	}
-}
-
-func New(username, password, mechanism, service, host string) (saslStepper, error) {
-	initOnce.Do(initSASL)
-	if initError != nil {
-		return nil, initError
-	}
-
-	ss := &saslSession{mech: mechanism}
-	if service == "" {
-		service = "mongodb"
-	}
-	if i := strings.Index(host, ":"); i >= 0 {
-		host = host[:i]
-	}
-	ss.callbacks = C.mgo_sasl_callbacks(ss.cstr(username), ss.cstr(password))
-	rc := C.sasl_client_new(ss.cstr(service), ss.cstr(host), nil, nil, ss.callbacks, 0, &ss.conn)
-	if rc != C.SASL_OK {
-		ss.Close()
-		return nil, saslError(rc, nil, "cannot create new SASL client")
-	}
-	return ss, nil
-}
-
-func (ss *saslSession) cstr(s string) *C.char {
-	cstr := C.CString(s)
-	ss.cstrings = append(ss.cstrings, cstr)
-	return cstr
-}
-
-func (ss *saslSession) Close() {
-	for _, cstr := range ss.cstrings {
-		C.free(unsafe.Pointer(cstr))
-	}
-	ss.cstrings = nil
-
-	if ss.callbacks != nil {
-		C.free(unsafe.Pointer(ss.callbacks))
-	}
-
-	// The documentation of SASL dispose makes it clear that this should only
-	// be done when the connection is done, not when the authentication phase
-	// is done, because an encryption layer may have been negotiated.
-	// Even then, we'll do this for now, because it's simpler and prevents
-	// keeping track of this state for every socket. If it breaks, we'll fix it.
-	C.sasl_dispose(&ss.conn)
-}
-
-func (ss *saslSession) Step(serverData []byte) (clientData []byte, done bool, err error) {
-	ss.step++
-	if ss.step > 10 {
-		return nil, false, fmt.Errorf("too many SASL steps without authentication")
-	}
-	var cclientData *C.char
-	var cclientDataLen C.uint
-	var rc C.int
-	if ss.step == 1 {
-		var mechanism *C.char // ignored - must match cred
-		rc = C.sasl_client_start(ss.conn, ss.cstr(ss.mech), nil, &cclientData, &cclientDataLen, &mechanism)
-	} else {
-		var cserverData *C.char
-		var cserverDataLen C.uint
-		if len(serverData) > 0 {
-			cserverData = (*C.char)(unsafe.Pointer(&serverData[0]))
-			cserverDataLen = C.uint(len(serverData))
-		}
-		rc = C.sasl_client_step(ss.conn, cserverData, cserverDataLen, nil, &cclientData, &cclientDataLen)
-	}
-	if cclientData != nil && cclientDataLen > 0 {
-		clientData = C.GoBytes(unsafe.Pointer(cclientData), C.int(cclientDataLen))
-	}
-	if rc == C.SASL_OK {
-		return clientData, true, nil
-	}
-	if rc == C.SASL_CONTINUE {
-		return clientData, false, nil
-	}
-	return nil, false, saslError(rc, ss.conn, "cannot establish SASL session")
-}
-
-func saslError(rc C.int, conn *C.sasl_conn_t, msg string) error {
-	var detail string
-	if conn == nil {
-		detail = C.GoString(C.sasl_errstring(rc, nil, nil))
-	} else {
-		detail = C.GoString(C.sasl_errdetail(conn))
-	}
-	return fmt.Errorf(msg + ": " + detail)
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.c b/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.c
deleted file mode 100644
index c359fd6..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.c
+++ /dev/null
@@ -1,122 +0,0 @@
-#include "sasl_windows.h"
-
-static const LPSTR SSPI_PACKAGE_NAME = "kerberos";
-
-SECURITY_STATUS SEC_ENTRY sspi_acquire_credentials_handle(CredHandle *cred_handle, char *username, char *password, char *domain)
-{
-	SEC_WINNT_AUTH_IDENTITY auth_identity;
-	SECURITY_INTEGER ignored;
-
-	auth_identity.Flags = SEC_WINNT_AUTH_IDENTITY_ANSI;
-	auth_identity.User = (LPSTR) username;
-	auth_identity.UserLength = strlen(username);
-	auth_identity.Password = NULL;
-	auth_identity.PasswordLength = 0;
-	if(password){
-		auth_identity.Password = (LPSTR) password;
-		auth_identity.PasswordLength = strlen(password);
-	}
-	auth_identity.Domain = (LPSTR) domain;
-	auth_identity.DomainLength = strlen(domain);
-	return call_sspi_acquire_credentials_handle(NULL, SSPI_PACKAGE_NAME, SECPKG_CRED_OUTBOUND, NULL, &auth_identity, NULL, NULL, cred_handle, &ignored);
-}
-
-int sspi_step(CredHandle *cred_handle, int has_context, CtxtHandle *context, PVOID buffer, ULONG buffer_length, PVOID *out_buffer, ULONG *out_buffer_length,  char *target)
-{
-	SecBufferDesc inbuf;
-	SecBuffer in_bufs[1];
-	SecBufferDesc outbuf;
-	SecBuffer out_bufs[1];
-
-	if (has_context > 0) {
-		// If we already have a context, we now have data to send.
-		// Put this data in an inbuf.
-		inbuf.ulVersion = SECBUFFER_VERSION;
-		inbuf.cBuffers = 1;
-		inbuf.pBuffers = in_bufs;
-		in_bufs[0].pvBuffer = buffer;
-		in_bufs[0].cbBuffer = buffer_length;
-		in_bufs[0].BufferType = SECBUFFER_TOKEN;
-	}
-
-	outbuf.ulVersion = SECBUFFER_VERSION;
-	outbuf.cBuffers = 1;
-	outbuf.pBuffers = out_bufs;
-	out_bufs[0].pvBuffer = NULL;
-	out_bufs[0].cbBuffer = 0;
-	out_bufs[0].BufferType = SECBUFFER_TOKEN;
-
-	ULONG context_attr = 0;
-
-	int ret = call_sspi_initialize_security_context(cred_handle,
-	          has_context > 0 ? context : NULL,
-	          (LPSTR) target,
-	          ISC_REQ_ALLOCATE_MEMORY | ISC_REQ_MUTUAL_AUTH,
-	          0,
-	          SECURITY_NETWORK_DREP,
-	          has_context > 0 ? &inbuf : NULL,
-	          0,
-	          context,
-	          &outbuf,
-	          &context_attr,
-	          NULL);
-
-	*out_buffer = malloc(out_bufs[0].cbBuffer);
-	*out_buffer_length = out_bufs[0].cbBuffer;
-	memcpy(*out_buffer, out_bufs[0].pvBuffer, *out_buffer_length);
-
-	return ret;
-}
-
-int sspi_send_client_authz_id(CtxtHandle *context, PVOID *buffer, ULONG *buffer_length, char *user_plus_realm)
-{
-	SecPkgContext_Sizes sizes;
-	SECURITY_STATUS status = call_sspi_query_context_attributes(context, SECPKG_ATTR_SIZES, &sizes);
-
-	if (status != SEC_E_OK) {
-		return status;
-	}
-
-	size_t user_plus_realm_length = strlen(user_plus_realm);
-	int msgSize = 4 + user_plus_realm_length;
-	char *msg = malloc((sizes.cbSecurityTrailer + msgSize + sizes.cbBlockSize) * sizeof(char));
-	msg[sizes.cbSecurityTrailer + 0] = 1;
-	msg[sizes.cbSecurityTrailer + 1] = 0;
-	msg[sizes.cbSecurityTrailer + 2] = 0;
-	msg[sizes.cbSecurityTrailer + 3] = 0;
-	memcpy(&msg[sizes.cbSecurityTrailer + 4], user_plus_realm, user_plus_realm_length);
-
-	SecBuffer wrapBufs[3];
-	SecBufferDesc wrapBufDesc;
-	wrapBufDesc.cBuffers = 3;
-	wrapBufDesc.pBuffers = wrapBufs;
-	wrapBufDesc.ulVersion = SECBUFFER_VERSION;
-
-	wrapBufs[0].cbBuffer = sizes.cbSecurityTrailer;
-	wrapBufs[0].BufferType = SECBUFFER_TOKEN;
-	wrapBufs[0].pvBuffer = msg;
-
-	wrapBufs[1].cbBuffer = msgSize;
-	wrapBufs[1].BufferType = SECBUFFER_DATA;
-	wrapBufs[1].pvBuffer = msg + sizes.cbSecurityTrailer;
-
-	wrapBufs[2].cbBuffer = sizes.cbBlockSize;
-	wrapBufs[2].BufferType = SECBUFFER_PADDING;
-	wrapBufs[2].pvBuffer = msg + sizes.cbSecurityTrailer + msgSize;
-
-	status = call_sspi_encrypt_message(context, SECQOP_WRAP_NO_ENCRYPT, &wrapBufDesc, 0);
-	if (status != SEC_E_OK) {
-		free(msg);
-		return status;
-	}
-
-	*buffer_length = wrapBufs[0].cbBuffer + wrapBufs[1].cbBuffer + wrapBufs[2].cbBuffer;
-	*buffer = malloc(*buffer_length);
-
-	memcpy(*buffer, wrapBufs[0].pvBuffer, wrapBufs[0].cbBuffer);
-	memcpy(*buffer + wrapBufs[0].cbBuffer, wrapBufs[1].pvBuffer, wrapBufs[1].cbBuffer);
-	memcpy(*buffer + wrapBufs[0].cbBuffer + wrapBufs[1].cbBuffer, wrapBufs[2].pvBuffer, wrapBufs[2].cbBuffer);
-
-	free(msg);
-	return SEC_E_OK;
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.go b/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.go
deleted file mode 100644
index d8ec001..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.go
+++ /dev/null
@@ -1,142 +0,0 @@
-package sasl
-
-// #include "sasl_windows.h"
-import "C"
-
-import (
-	"fmt"
-	"strings"
-	"sync"
-	"unsafe"
-)
-
-type saslStepper interface {
-	Step(serverData []byte) (clientData []byte, done bool, err error)
-	Close()
-}
-
-type saslSession struct {
-	// Credentials
-	mech          string
-	service       string
-	host          string
-	userPlusRealm string
-	target        string
-	domain        string
-
-	// Internal state
-	authComplete bool
-	errored      bool
-	step         int
-
-	// C internal state
-	credHandle C.CredHandle
-	context    C.CtxtHandle
-	hasContext C.int
-
-	// Keep track of pointers we need to explicitly free
-	stringsToFree []*C.char
-}
-
-var initError error
-var initOnce sync.Once
-
-func initSSPI() {
-	rc := C.load_secur32_dll()
-	if rc != 0 {
-		initError = fmt.Errorf("Error loading libraries: %v", rc)
-	}
-}
-
-func New(username, password, mechanism, service, host string) (saslStepper, error) {
-	initOnce.Do(initSSPI)
-	ss := &saslSession{mech: mechanism, hasContext: 0, userPlusRealm: username}
-	if service == "" {
-		service = "mongodb"
-	}
-	if i := strings.Index(host, ":"); i >= 0 {
-		host = host[:i]
-	}
-	ss.service = service
-	ss.host = host
-
-	usernameComponents := strings.Split(username, "@")
-	if len(usernameComponents) < 2 {
-		return nil, fmt.Errorf("Username '%v' doesn't contain a realm!", username)
-	}
-	user := usernameComponents[0]
-	ss.domain = usernameComponents[1]
-	ss.target = fmt.Sprintf("%s/%s", ss.service, ss.host)
-
-	var status C.SECURITY_STATUS
-	// Step 0: call AcquireCredentialsHandle to get a nice SSPI CredHandle
-	if len(password) > 0 {
-		status = C.sspi_acquire_credentials_handle(&ss.credHandle, ss.cstr(user), ss.cstr(password), ss.cstr(ss.domain))
-	} else {
-		status = C.sspi_acquire_credentials_handle(&ss.credHandle, ss.cstr(user), nil, ss.cstr(ss.domain))
-	}
-	if status != C.SEC_E_OK {
-		ss.errored = true
-		return nil, fmt.Errorf("Couldn't create new SSPI client, error code %v", status)
-	}
-	return ss, nil
-}
-
-func (ss *saslSession) cstr(s string) *C.char {
-	cstr := C.CString(s)
-	ss.stringsToFree = append(ss.stringsToFree, cstr)
-	return cstr
-}
-
-func (ss *saslSession) Close() {
-	for _, cstr := range ss.stringsToFree {
-		C.free(unsafe.Pointer(cstr))
-	}
-}
-
-func (ss *saslSession) Step(serverData []byte) (clientData []byte, done bool, err error) {
-	ss.step++
-	if ss.step > 10 {
-		return nil, false, fmt.Errorf("too many SSPI steps without authentication")
-	}
-	var buffer C.PVOID
-	var bufferLength C.ULONG
-	var outBuffer C.PVOID
-	var outBufferLength C.ULONG
-	if len(serverData) > 0 {
-		buffer = (C.PVOID)(unsafe.Pointer(&serverData[0]))
-		bufferLength = C.ULONG(len(serverData))
-	}
-	var status C.int
-	if ss.authComplete {
-		// Step 3: last bit of magic to use the correct server credentials
-		status = C.sspi_send_client_authz_id(&ss.context, &outBuffer, &outBufferLength, ss.cstr(ss.userPlusRealm))
-	} else {
-		// Step 1 + Step 2: set up security context with the server and TGT
-		status = C.sspi_step(&ss.credHandle, ss.hasContext, &ss.context, buffer, bufferLength, &outBuffer, &outBufferLength, ss.cstr(ss.target))
-	}
-	if outBuffer != C.PVOID(nil) {
-		defer C.free(unsafe.Pointer(outBuffer))
-	}
-	if status != C.SEC_E_OK && status != C.SEC_I_CONTINUE_NEEDED {
-		ss.errored = true
-		return nil, false, ss.handleSSPIErrorCode(status)
-	}
-
-	clientData = C.GoBytes(unsafe.Pointer(outBuffer), C.int(outBufferLength))
-	if status == C.SEC_E_OK {
-		ss.authComplete = true
-		return clientData, true, nil
-	} else {
-		ss.hasContext = 1
-		return clientData, false, nil
-	}
-}
-
-func (ss *saslSession) handleSSPIErrorCode(code C.int) error {
-	switch {
-	case code == C.SEC_E_TARGET_UNKNOWN:
-		return fmt.Errorf("Target %v@%v not found", ss.target, ss.domain)
-	}
-	return fmt.Errorf("Unknown error doing step %v, error code %v", ss.step, code)
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.h b/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.h
deleted file mode 100644
index a6b0395..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/sasl/sasl_windows.h
+++ /dev/null
@@ -1,7 +0,0 @@
-#include <windows.h>
-
-#include "sspi_windows.h"
-
-SECURITY_STATUS SEC_ENTRY sspi_acquire_credentials_handle(CredHandle* cred_handle, char* username, char* password, char* domain);
-int sspi_step(CredHandle* cred_handle, int has_context, CtxtHandle* context, PVOID buffer, ULONG buffer_length, PVOID* out_buffer, ULONG* out_buffer_length, char* target);
-int sspi_send_client_authz_id(CtxtHandle* context, PVOID* buffer, ULONG* buffer_length, char* user_plus_realm);
diff --git a/vendor/gopkg.in/mgo.v2/internal/sasl/sspi_windows.c b/vendor/gopkg.in/mgo.v2/internal/sasl/sspi_windows.c
deleted file mode 100644
index 63f9a6f..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/sasl/sspi_windows.c
+++ /dev/null
@@ -1,96 +0,0 @@
-// Code adapted from the NodeJS kerberos library:
-// 
-//   https://github.com/christkv/kerberos/tree/master/lib/win32/kerberos_sspi.c
-//
-// Under the terms of the Apache License, Version 2.0:
-//
-//   http://www.apache.org/licenses/LICENSE-2.0
-//
-#include <stdlib.h>
-
-#include "sspi_windows.h"
-
-static HINSTANCE sspi_secur32_dll = NULL;
-
-int load_secur32_dll()
-{
-	sspi_secur32_dll = LoadLibrary("secur32.dll");
-	if (sspi_secur32_dll == NULL) {
-		return GetLastError();
-	}
-	return 0;
-}
-
-SECURITY_STATUS SEC_ENTRY call_sspi_encrypt_message(PCtxtHandle phContext, unsigned long fQOP, PSecBufferDesc pMessage, unsigned long MessageSeqNo)
-{
-	if (sspi_secur32_dll == NULL) {
-		return -1;
-	}
-	encryptMessage_fn pfn_encryptMessage = (encryptMessage_fn) GetProcAddress(sspi_secur32_dll, "EncryptMessage");
-	if (!pfn_encryptMessage) {
-		return -2;
-	}
-	return (*pfn_encryptMessage)(phContext, fQOP, pMessage, MessageSeqNo);
-}
-
-SECURITY_STATUS SEC_ENTRY call_sspi_acquire_credentials_handle(
-	LPSTR pszPrincipal, LPSTR pszPackage, unsigned long fCredentialUse,
-        void *pvLogonId, void *pAuthData, SEC_GET_KEY_FN pGetKeyFn, void *pvGetKeyArgument,
-        PCredHandle phCredential, PTimeStamp ptsExpiry)
-{
-	if (sspi_secur32_dll == NULL) {
-		return -1;
-	}
-	acquireCredentialsHandle_fn pfn_acquireCredentialsHandle;
-#ifdef _UNICODE
-	pfn_acquireCredentialsHandle = (acquireCredentialsHandle_fn) GetProcAddress(sspi_secur32_dll, "AcquireCredentialsHandleW");
-#else
-	pfn_acquireCredentialsHandle = (acquireCredentialsHandle_fn) GetProcAddress(sspi_secur32_dll, "AcquireCredentialsHandleA");
-#endif
-	if (!pfn_acquireCredentialsHandle) {
-		return -2;
-	}
-	return (*pfn_acquireCredentialsHandle)(
-		pszPrincipal, pszPackage, fCredentialUse, pvLogonId, pAuthData,
-	        pGetKeyFn, pvGetKeyArgument, phCredential, ptsExpiry);
-}
-
-SECURITY_STATUS SEC_ENTRY call_sspi_initialize_security_context(
-	PCredHandle phCredential, PCtxtHandle phContext, LPSTR pszTargetName,
-	unsigned long fContextReq, unsigned long Reserved1, unsigned long TargetDataRep,
-	PSecBufferDesc pInput, unsigned long Reserved2, PCtxtHandle phNewContext,
-	PSecBufferDesc pOutput, unsigned long *pfContextAttr, PTimeStamp ptsExpiry)
-{
-	if (sspi_secur32_dll == NULL) {
-		return -1;
-	}
-	initializeSecurityContext_fn pfn_initializeSecurityContext;
-#ifdef _UNICODE
-	pfn_initializeSecurityContext = (initializeSecurityContext_fn) GetProcAddress(sspi_secur32_dll, "InitializeSecurityContextW");
-#else
-	pfn_initializeSecurityContext = (initializeSecurityContext_fn) GetProcAddress(sspi_secur32_dll, "InitializeSecurityContextA");
-#endif
-	if (!pfn_initializeSecurityContext) {
-		return -2;
-	}
-	return (*pfn_initializeSecurityContext)(
-		phCredential, phContext, pszTargetName, fContextReq, Reserved1, TargetDataRep,
-		pInput, Reserved2, phNewContext, pOutput, pfContextAttr, ptsExpiry);
-}
-
-SECURITY_STATUS SEC_ENTRY call_sspi_query_context_attributes(PCtxtHandle phContext, unsigned long ulAttribute, void *pBuffer)
-{
-	if (sspi_secur32_dll == NULL) {
-		return -1;
-	}
-	queryContextAttributes_fn pfn_queryContextAttributes;
-#ifdef _UNICODE
-	pfn_queryContextAttributes = (queryContextAttributes_fn) GetProcAddress(sspi_secur32_dll, "QueryContextAttributesW");
-#else
-	pfn_queryContextAttributes = (queryContextAttributes_fn) GetProcAddress(sspi_secur32_dll, "QueryContextAttributesA");
-#endif
-	if (!pfn_queryContextAttributes) {
-		return -2;
-	}
-	return (*pfn_queryContextAttributes)(phContext, ulAttribute, pBuffer);
-}
diff --git a/vendor/gopkg.in/mgo.v2/internal/sasl/sspi_windows.h b/vendor/gopkg.in/mgo.v2/internal/sasl/sspi_windows.h
deleted file mode 100644
index d283270..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/sasl/sspi_windows.h
+++ /dev/null
@@ -1,70 +0,0 @@
-// Code adapted from the NodeJS kerberos library:
-// 
-//   https://github.com/christkv/kerberos/tree/master/lib/win32/kerberos_sspi.h
-//
-// Under the terms of the Apache License, Version 2.0:
-//
-//   http://www.apache.org/licenses/LICENSE-2.0
-//
-#ifndef SSPI_WINDOWS_H
-#define SSPI_WINDOWS_H
-
-#define SECURITY_WIN32 1
-
-#include <windows.h>
-#include <sspi.h>
-
-int load_secur32_dll();
-
-SECURITY_STATUS SEC_ENTRY call_sspi_encrypt_message(PCtxtHandle phContext, unsigned long fQOP, PSecBufferDesc pMessage, unsigned long MessageSeqNo);
-
-typedef DWORD (WINAPI *encryptMessage_fn)(PCtxtHandle phContext, ULONG fQOP, PSecBufferDesc pMessage, ULONG MessageSeqNo);
-
-SECURITY_STATUS SEC_ENTRY call_sspi_acquire_credentials_handle(
-    LPSTR pszPrincipal,             // Name of principal
-    LPSTR pszPackage,               // Name of package
-    unsigned long fCredentialUse,   // Flags indicating use
-    void *pvLogonId,                // Pointer to logon ID
-    void *pAuthData,                // Package specific data
-    SEC_GET_KEY_FN pGetKeyFn,       // Pointer to GetKey() func
-    void *pvGetKeyArgument,         // Value to pass to GetKey()
-    PCredHandle phCredential,       // (out) Cred Handle
-    PTimeStamp ptsExpiry            // (out) Lifetime (optional)
-);
-
-typedef DWORD (WINAPI *acquireCredentialsHandle_fn)(
-    LPSTR pszPrincipal, LPSTR pszPackage, unsigned long fCredentialUse,
-    void *pvLogonId, void *pAuthData, SEC_GET_KEY_FN pGetKeyFn, void *pvGetKeyArgument,
-    PCredHandle phCredential, PTimeStamp ptsExpiry
-);
-
-SECURITY_STATUS SEC_ENTRY call_sspi_initialize_security_context(
-    PCredHandle phCredential,       // Cred to base context
-    PCtxtHandle phContext,          // Existing context (OPT)
-    LPSTR pszTargetName,            // Name of target
-    unsigned long fContextReq,      // Context Requirements
-    unsigned long Reserved1,        // Reserved, MBZ
-    unsigned long TargetDataRep,    // Data rep of target
-    PSecBufferDesc pInput,          // Input Buffers
-    unsigned long Reserved2,        // Reserved, MBZ
-    PCtxtHandle phNewContext,       // (out) New Context handle
-    PSecBufferDesc pOutput,         // (inout) Output Buffers
-    unsigned long *pfContextAttr,   // (out) Context attrs
-    PTimeStamp ptsExpiry            // (out) Life span (OPT)
-);
-
-typedef DWORD (WINAPI *initializeSecurityContext_fn)(
-    PCredHandle phCredential, PCtxtHandle phContext, LPSTR pszTargetName, unsigned long fContextReq,
-    unsigned long Reserved1, unsigned long TargetDataRep, PSecBufferDesc pInput, unsigned long Reserved2,
-    PCtxtHandle phNewContext, PSecBufferDesc pOutput, unsigned long *pfContextAttr, PTimeStamp ptsExpiry);
-
-SECURITY_STATUS SEC_ENTRY call_sspi_query_context_attributes(
-    PCtxtHandle phContext,          // Context to query
-    unsigned long ulAttribute,      // Attribute to query
-    void *pBuffer                   // Buffer for attributes
-);
-
-typedef DWORD (WINAPI *queryContextAttributes_fn)(
-    PCtxtHandle phContext, unsigned long ulAttribute, void *pBuffer);
-
-#endif // SSPI_WINDOWS_H
diff --git a/vendor/gopkg.in/mgo.v2/internal/scram/scram.go b/vendor/gopkg.in/mgo.v2/internal/scram/scram.go
deleted file mode 100644
index 80cda91..0000000
--- a/vendor/gopkg.in/mgo.v2/internal/scram/scram.go
+++ /dev/null
@@ -1,266 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2014 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// Pacakage scram implements a SCRAM-{SHA-1,etc} client per RFC5802.
-//
-// http://tools.ietf.org/html/rfc5802
-//
-package scram
-
-import (
-	"bytes"
-	"crypto/hmac"
-	"crypto/rand"
-	"encoding/base64"
-	"fmt"
-	"hash"
-	"strconv"
-	"strings"
-)
-
-// Client implements a SCRAM-* client (SCRAM-SHA-1, SCRAM-SHA-256, etc).
-//
-// A Client may be used within a SASL conversation with logic resembling:
-//
-//    var in []byte
-//    var client = scram.NewClient(sha1.New, user, pass)
-//    for client.Step(in) {
-//            out := client.Out()
-//            // send out to server
-//            in := serverOut
-//    }
-//    if client.Err() != nil {
-//            // auth failed
-//    }
-//
-type Client struct {
-	newHash func() hash.Hash
-
-	user string
-	pass string
-	step int
-	out  bytes.Buffer
-	err  error
-
-	clientNonce []byte
-	serverNonce []byte
-	saltedPass  []byte
-	authMsg     bytes.Buffer
-}
-
-// NewClient returns a new SCRAM-* client with the provided hash algorithm.
-//
-// For SCRAM-SHA-1, for example, use:
-//
-//    client := scram.NewClient(sha1.New, user, pass)
-//
-func NewClient(newHash func() hash.Hash, user, pass string) *Client {
-	c := &Client{
-		newHash: newHash,
-		user:    user,
-		pass:    pass,
-	}
-	c.out.Grow(256)
-	c.authMsg.Grow(256)
-	return c
-}
-
-// Out returns the data to be sent to the server in the current step.
-func (c *Client) Out() []byte {
-	if c.out.Len() == 0 {
-		return nil
-	}
-	return c.out.Bytes()
-}
-
-// Err returns the error that ocurred, or nil if there were no errors.
-func (c *Client) Err() error {
-	return c.err
-}
-
-// SetNonce sets the client nonce to the provided value.
-// If not set, the nonce is generated automatically out of crypto/rand on the first step.
-func (c *Client) SetNonce(nonce []byte) {
-	c.clientNonce = nonce
-}
-
-var escaper = strings.NewReplacer("=", "=3D", ",", "=2C")
-
-// Step processes the incoming data from the server and makes the
-// next round of data for the server available via Client.Out.
-// Step returns false if there are no errors and more data is
-// still expected.
-func (c *Client) Step(in []byte) bool {
-	c.out.Reset()
-	if c.step > 2 || c.err != nil {
-		return false
-	}
-	c.step++
-	switch c.step {
-	case 1:
-		c.err = c.step1(in)
-	case 2:
-		c.err = c.step2(in)
-	case 3:
-		c.err = c.step3(in)
-	}
-	return c.step > 2 || c.err != nil
-}
-
-func (c *Client) step1(in []byte) error {
-	if len(c.clientNonce) == 0 {
-		const nonceLen = 6
-		buf := make([]byte, nonceLen + b64.EncodedLen(nonceLen))
-		if _, err := rand.Read(buf[:nonceLen]); err != nil {
-			return fmt.Errorf("cannot read random SCRAM-SHA-1 nonce from operating system: %v", err)
-		}
-		c.clientNonce = buf[nonceLen:]
-		b64.Encode(c.clientNonce, buf[:nonceLen])
-	}
-	c.authMsg.WriteString("n=")
-	escaper.WriteString(&c.authMsg, c.user)
-	c.authMsg.WriteString(",r=")
-	c.authMsg.Write(c.clientNonce)
-
-	c.out.WriteString("n,,")
-	c.out.Write(c.authMsg.Bytes())
-	return nil
-}
-
-var b64 = base64.StdEncoding
-
-func (c *Client) step2(in []byte) error {
-	c.authMsg.WriteByte(',')
-	c.authMsg.Write(in)
-
-	fields := bytes.Split(in, []byte(","))
-	if len(fields) != 3 {
-		return fmt.Errorf("expected 3 fields in first SCRAM-SHA-1 server message, got %d: %q", len(fields), in)
-	}
-	if !bytes.HasPrefix(fields[0], []byte("r=")) || len(fields[0]) < 2 {
-		return fmt.Errorf("server sent an invalid SCRAM-SHA-1 nonce: %q", fields[0])
-	}
-	if !bytes.HasPrefix(fields[1], []byte("s=")) || len(fields[1]) < 6 {
-		return fmt.Errorf("server sent an invalid SCRAM-SHA-1 salt: %q", fields[1])
-	}
-	if !bytes.HasPrefix(fields[2], []byte("i=")) || len(fields[2]) < 6 {
-		return fmt.Errorf("server sent an invalid SCRAM-SHA-1 iteration count: %q", fields[2])
-	}
-
-	c.serverNonce = fields[0][2:]
-	if !bytes.HasPrefix(c.serverNonce, c.clientNonce) {
-		return fmt.Errorf("server SCRAM-SHA-1 nonce is not prefixed by client nonce: got %q, want %q+\"...\"", c.serverNonce, c.clientNonce)
-	}
-
-	salt := make([]byte, b64.DecodedLen(len(fields[1][2:])))
-	n, err := b64.Decode(salt, fields[1][2:])
-	if err != nil {
-		return fmt.Errorf("cannot decode SCRAM-SHA-1 salt sent by server: %q", fields[1])
-	}
-	salt = salt[:n]
-	iterCount, err := strconv.Atoi(string(fields[2][2:]))
-	if err != nil {
-		return fmt.Errorf("server sent an invalid SCRAM-SHA-1 iteration count: %q", fields[2])
-	}
-	c.saltPassword(salt, iterCount)
-
-	c.authMsg.WriteString(",c=biws,r=")
-	c.authMsg.Write(c.serverNonce)
-
-	c.out.WriteString("c=biws,r=")
-	c.out.Write(c.serverNonce)
-	c.out.WriteString(",p=")
-	c.out.Write(c.clientProof())
-	return nil
-}
-
-func (c *Client) step3(in []byte) error {
-	var isv, ise bool
-	var fields = bytes.Split(in, []byte(","))
-	if len(fields) == 1 {
-		isv = bytes.HasPrefix(fields[0], []byte("v="))
-		ise = bytes.HasPrefix(fields[0], []byte("e="))
-	}
-	if ise {
-		return fmt.Errorf("SCRAM-SHA-1 authentication error: %s", fields[0][2:])
-	} else if !isv {
-		return fmt.Errorf("unsupported SCRAM-SHA-1 final message from server: %q", in)
-	}
-	if !bytes.Equal(c.serverSignature(), fields[0][2:]) {
-		return fmt.Errorf("cannot authenticate SCRAM-SHA-1 server signature: %q", fields[0][2:])
-	}
-	return nil
-}
-
-func (c *Client) saltPassword(salt []byte, iterCount int) {
-	mac := hmac.New(c.newHash, []byte(c.pass))
-	mac.Write(salt)
-	mac.Write([]byte{0, 0, 0, 1})
-	ui := mac.Sum(nil)
-	hi := make([]byte, len(ui))
-	copy(hi, ui)
-	for i := 1; i < iterCount; i++ {
-		mac.Reset()
-		mac.Write(ui)
-		mac.Sum(ui[:0])
-		for j, b := range ui {
-			hi[j] ^= b
-		}
-	}
-	c.saltedPass = hi
-}
-
-func (c *Client) clientProof() []byte {
-	mac := hmac.New(c.newHash, c.saltedPass)
-	mac.Write([]byte("Client Key"))
-	clientKey := mac.Sum(nil)
-	hash := c.newHash()
-	hash.Write(clientKey)
-	storedKey := hash.Sum(nil)
-	mac = hmac.New(c.newHash, storedKey)
-	mac.Write(c.authMsg.Bytes())
-	clientProof := mac.Sum(nil)
-	for i, b := range clientKey {
-		clientProof[i] ^= b
-	}
-	clientProof64 := make([]byte, b64.EncodedLen(len(clientProof)))
-	b64.Encode(clientProof64, clientProof)
-	return clientProof64
-}
-
-func (c *Client) serverSignature() []byte {
-	mac := hmac.New(c.newHash, c.saltedPass)
-	mac.Write([]byte("Server Key"))
-	serverKey := mac.Sum(nil)
-
-	mac = hmac.New(c.newHash, serverKey)
-	mac.Write(c.authMsg.Bytes())
-	serverSignature := mac.Sum(nil)
-
-	encoded := make([]byte, b64.EncodedLen(len(serverSignature)))
-	b64.Encode(encoded, serverSignature)
-	return encoded
-}
diff --git a/vendor/gopkg.in/mgo.v2/log.go b/vendor/gopkg.in/mgo.v2/log.go
deleted file mode 100644
index 53eb423..0000000
--- a/vendor/gopkg.in/mgo.v2/log.go
+++ /dev/null
@@ -1,133 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"fmt"
-	"sync"
-)
-
-// ---------------------------------------------------------------------------
-// Logging integration.
-
-// Avoid importing the log type information unnecessarily.  There's a small cost
-// associated with using an interface rather than the type.  Depending on how
-// often the logger is plugged in, it would be worth using the type instead.
-type log_Logger interface {
-	Output(calldepth int, s string) error
-}
-
-var (
-	globalLogger log_Logger
-	globalDebug  bool
-	globalMutex  sync.Mutex
-)
-
-// RACE WARNING: There are known data races when logging, which are manually
-// silenced when the race detector is in use. These data races won't be
-// observed in typical use, because logging is supposed to be set up once when
-// the application starts. Having raceDetector as a constant, the compiler
-// should elide the locks altogether in actual use.
-
-// Specify the *log.Logger object where log messages should be sent to.
-func SetLogger(logger log_Logger) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	globalLogger = logger
-}
-
-// Enable the delivery of debug messages to the logger.  Only meaningful
-// if a logger is also set.
-func SetDebug(debug bool) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	globalDebug = debug
-}
-
-func log(v ...interface{}) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	if globalLogger != nil {
-		globalLogger.Output(2, fmt.Sprint(v...))
-	}
-}
-
-func logln(v ...interface{}) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	if globalLogger != nil {
-		globalLogger.Output(2, fmt.Sprintln(v...))
-	}
-}
-
-func logf(format string, v ...interface{}) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	if globalLogger != nil {
-		globalLogger.Output(2, fmt.Sprintf(format, v...))
-	}
-}
-
-func debug(v ...interface{}) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	if globalDebug && globalLogger != nil {
-		globalLogger.Output(2, fmt.Sprint(v...))
-	}
-}
-
-func debugln(v ...interface{}) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	if globalDebug && globalLogger != nil {
-		globalLogger.Output(2, fmt.Sprintln(v...))
-	}
-}
-
-func debugf(format string, v ...interface{}) {
-	if raceDetector {
-		globalMutex.Lock()
-		defer globalMutex.Unlock()
-	}
-	if globalDebug && globalLogger != nil {
-		globalLogger.Output(2, fmt.Sprintf(format, v...))
-	}
-}
diff --git a/vendor/gopkg.in/mgo.v2/queue.go b/vendor/gopkg.in/mgo.v2/queue.go
deleted file mode 100644
index e9245de..0000000
--- a/vendor/gopkg.in/mgo.v2/queue.go
+++ /dev/null
@@ -1,91 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-type queue struct {
-	elems               []interface{}
-	nelems, popi, pushi int
-}
-
-func (q *queue) Len() int {
-	return q.nelems
-}
-
-func (q *queue) Push(elem interface{}) {
-	//debugf("Pushing(pushi=%d popi=%d cap=%d): %#v\n",
-	//       q.pushi, q.popi, len(q.elems), elem)
-	if q.nelems == len(q.elems) {
-		q.expand()
-	}
-	q.elems[q.pushi] = elem
-	q.nelems++
-	q.pushi = (q.pushi + 1) % len(q.elems)
-	//debugf(" Pushed(pushi=%d popi=%d cap=%d): %#v\n",
-	//       q.pushi, q.popi, len(q.elems), elem)
-}
-
-func (q *queue) Pop() (elem interface{}) {
-	//debugf("Popping(pushi=%d popi=%d cap=%d)\n",
-	//       q.pushi, q.popi, len(q.elems))
-	if q.nelems == 0 {
-		return nil
-	}
-	elem = q.elems[q.popi]
-	q.elems[q.popi] = nil // Help GC.
-	q.nelems--
-	q.popi = (q.popi + 1) % len(q.elems)
-	//debugf(" Popped(pushi=%d popi=%d cap=%d): %#v\n",
-	//       q.pushi, q.popi, len(q.elems), elem)
-	return elem
-}
-
-func (q *queue) expand() {
-	curcap := len(q.elems)
-	var newcap int
-	if curcap == 0 {
-		newcap = 8
-	} else if curcap < 1024 {
-		newcap = curcap * 2
-	} else {
-		newcap = curcap + (curcap / 4)
-	}
-	elems := make([]interface{}, newcap)
-
-	if q.popi == 0 {
-		copy(elems, q.elems)
-		q.pushi = curcap
-	} else {
-		newpopi := newcap - (curcap - q.popi)
-		copy(elems, q.elems[:q.popi])
-		copy(elems[newpopi:], q.elems[q.popi:])
-		q.popi = newpopi
-	}
-	for i := range q.elems {
-		q.elems[i] = nil // Help GC.
-	}
-	q.elems = elems
-}
diff --git a/vendor/gopkg.in/mgo.v2/raceoff.go b/vendor/gopkg.in/mgo.v2/raceoff.go
deleted file mode 100644
index e60b141..0000000
--- a/vendor/gopkg.in/mgo.v2/raceoff.go
+++ /dev/null
@@ -1,5 +0,0 @@
-// +build !race
-
-package mgo
-
-const raceDetector = false
diff --git a/vendor/gopkg.in/mgo.v2/raceon.go b/vendor/gopkg.in/mgo.v2/raceon.go
deleted file mode 100644
index 737b08e..0000000
--- a/vendor/gopkg.in/mgo.v2/raceon.go
+++ /dev/null
@@ -1,5 +0,0 @@
-// +build race
-
-package mgo
-
-const raceDetector = true
diff --git a/vendor/gopkg.in/mgo.v2/saslimpl.go b/vendor/gopkg.in/mgo.v2/saslimpl.go
deleted file mode 100644
index 0d25f25..0000000
--- a/vendor/gopkg.in/mgo.v2/saslimpl.go
+++ /dev/null
@@ -1,11 +0,0 @@
-//+build sasl
-
-package mgo
-
-import (
-	"gopkg.in/mgo.v2/internal/sasl"
-)
-
-func saslNew(cred Credential, host string) (saslStepper, error) {
-	return sasl.New(cred.Username, cred.Password, cred.Mechanism, cred.Service, host)
-}
diff --git a/vendor/gopkg.in/mgo.v2/saslstub.go b/vendor/gopkg.in/mgo.v2/saslstub.go
deleted file mode 100644
index 6e9e309..0000000
--- a/vendor/gopkg.in/mgo.v2/saslstub.go
+++ /dev/null
@@ -1,11 +0,0 @@
-//+build !sasl
-
-package mgo
-
-import (
-	"fmt"
-)
-
-func saslNew(cred Credential, host string) (saslStepper, error) {
-	return nil, fmt.Errorf("SASL support not enabled during build (-tags sasl)")
-}
diff --git a/vendor/gopkg.in/mgo.v2/server.go b/vendor/gopkg.in/mgo.v2/server.go
deleted file mode 100644
index 3925986..0000000
--- a/vendor/gopkg.in/mgo.v2/server.go
+++ /dev/null
@@ -1,463 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"errors"
-	"net"
-	"sort"
-	"sync"
-	"time"
-
-	"gopkg.in/mgo.v2/bson"
-)
-
-// ---------------------------------------------------------------------------
-// Mongo server encapsulation.
-
-type mongoServer struct {
-	sync.RWMutex
-	Addr          string
-	ResolvedAddr  string
-	tcpaddr       *net.TCPAddr
-	unusedSockets []*mongoSocket
-	liveSockets   []*mongoSocket
-	closed        bool
-	abended       bool
-	sync          chan bool
-	dial          dialer
-	pingValue     time.Duration
-	pingIndex     int
-	pingCount     uint32
-	pingWindow    [6]time.Duration
-	info          *mongoServerInfo
-}
-
-type dialer struct {
-	old func(addr net.Addr) (net.Conn, error)
-	new func(addr *ServerAddr) (net.Conn, error)
-}
-
-func (dial dialer) isSet() bool {
-	return dial.old != nil || dial.new != nil
-}
-
-type mongoServerInfo struct {
-	Master         bool
-	Mongos         bool
-	Tags           bson.D
-	MaxWireVersion int
-	SetName        string
-}
-
-var defaultServerInfo mongoServerInfo
-
-func newServer(addr string, tcpaddr *net.TCPAddr, sync chan bool, dial dialer) *mongoServer {
-	server := &mongoServer{
-		Addr:         addr,
-		ResolvedAddr: tcpaddr.String(),
-		tcpaddr:      tcpaddr,
-		sync:         sync,
-		dial:         dial,
-		info:         &defaultServerInfo,
-		pingValue:    time.Hour, // Push it back before an actual ping.
-	}
-	go server.pinger(true)
-	return server
-}
-
-var errPoolLimit = errors.New("per-server connection limit reached")
-var errServerClosed = errors.New("server was closed")
-
-// AcquireSocket returns a socket for communicating with the server.
-// This will attempt to reuse an old connection, if one is available. Otherwise,
-// it will establish a new one. The returned socket is owned by the call site,
-// and will return to the cache when the socket has its Release method called
-// the same number of times as AcquireSocket + Acquire were called for it.
-// If the poolLimit argument is greater than zero and the number of sockets in
-// use in this server is greater than the provided limit, errPoolLimit is
-// returned.
-func (server *mongoServer) AcquireSocket(poolLimit int, timeout time.Duration) (socket *mongoSocket, abended bool, err error) {
-	for {
-		server.Lock()
-		abended = server.abended
-		if server.closed {
-			server.Unlock()
-			return nil, abended, errServerClosed
-		}
-		n := len(server.unusedSockets)
-		if poolLimit > 0 && len(server.liveSockets)-n >= poolLimit {
-			server.Unlock()
-			return nil, false, errPoolLimit
-		}
-		if n > 0 {
-			socket = server.unusedSockets[n-1]
-			server.unusedSockets[n-1] = nil // Help GC.
-			server.unusedSockets = server.unusedSockets[:n-1]
-			info := server.info
-			server.Unlock()
-			err = socket.InitialAcquire(info, timeout)
-			if err != nil {
-				continue
-			}
-		} else {
-			server.Unlock()
-			socket, err = server.Connect(timeout)
-			if err == nil {
-				server.Lock()
-				// We've waited for the Connect, see if we got
-				// closed in the meantime
-				if server.closed {
-					server.Unlock()
-					socket.Release()
-					socket.Close()
-					return nil, abended, errServerClosed
-				}
-				server.liveSockets = append(server.liveSockets, socket)
-				server.Unlock()
-			}
-		}
-		return
-	}
-	panic("unreachable")
-}
-
-// Connect establishes a new connection to the server. This should
-// generally be done through server.AcquireSocket().
-func (server *mongoServer) Connect(timeout time.Duration) (*mongoSocket, error) {
-	server.RLock()
-	master := server.info.Master
-	dial := server.dial
-	server.RUnlock()
-
-	logf("Establishing new connection to %s (timeout=%s)...", server.Addr, timeout)
-	var conn net.Conn
-	var err error
-	switch {
-	case !dial.isSet():
-		// Cannot do this because it lacks timeout support. :-(
-		//conn, err = net.DialTCP("tcp", nil, server.tcpaddr)
-		conn, err = net.DialTimeout("tcp", server.ResolvedAddr, timeout)
-		if tcpconn, ok := conn.(*net.TCPConn); ok {
-			tcpconn.SetKeepAlive(true)
-		} else if err == nil {
-			panic("internal error: obtained TCP connection is not a *net.TCPConn!?")
-		}
-	case dial.old != nil:
-		conn, err = dial.old(server.tcpaddr)
-	case dial.new != nil:
-		conn, err = dial.new(&ServerAddr{server.Addr, server.tcpaddr})
-	default:
-		panic("dialer is set, but both dial.old and dial.new are nil")
-	}
-	if err != nil {
-		logf("Connection to %s failed: %v", server.Addr, err.Error())
-		return nil, err
-	}
-	logf("Connection to %s established.", server.Addr)
-
-	stats.conn(+1, master)
-	return newSocket(server, conn, timeout), nil
-}
-
-// Close forces closing all sockets that are alive, whether
-// they're currently in use or not.
-func (server *mongoServer) Close() {
-	server.Lock()
-	server.closed = true
-	liveSockets := server.liveSockets
-	unusedSockets := server.unusedSockets
-	server.liveSockets = nil
-	server.unusedSockets = nil
-	server.Unlock()
-	logf("Connections to %s closing (%d live sockets).", server.Addr, len(liveSockets))
-	for i, s := range liveSockets {
-		s.Close()
-		liveSockets[i] = nil
-	}
-	for i := range unusedSockets {
-		unusedSockets[i] = nil
-	}
-}
-
-// RecycleSocket puts socket back into the unused cache.
-func (server *mongoServer) RecycleSocket(socket *mongoSocket) {
-	server.Lock()
-	if !server.closed {
-		server.unusedSockets = append(server.unusedSockets, socket)
-	}
-	server.Unlock()
-}
-
-func removeSocket(sockets []*mongoSocket, socket *mongoSocket) []*mongoSocket {
-	for i, s := range sockets {
-		if s == socket {
-			copy(sockets[i:], sockets[i+1:])
-			n := len(sockets) - 1
-			sockets[n] = nil
-			sockets = sockets[:n]
-			break
-		}
-	}
-	return sockets
-}
-
-// AbendSocket notifies the server that the given socket has terminated
-// abnormally, and thus should be discarded rather than cached.
-func (server *mongoServer) AbendSocket(socket *mongoSocket) {
-	server.Lock()
-	server.abended = true
-	if server.closed {
-		server.Unlock()
-		return
-	}
-	server.liveSockets = removeSocket(server.liveSockets, socket)
-	server.unusedSockets = removeSocket(server.unusedSockets, socket)
-	server.Unlock()
-	// Maybe just a timeout, but suggest a cluster sync up just in case.
-	select {
-	case server.sync <- true:
-	default:
-	}
-}
-
-func (server *mongoServer) SetInfo(info *mongoServerInfo) {
-	server.Lock()
-	server.info = info
-	server.Unlock()
-}
-
-func (server *mongoServer) Info() *mongoServerInfo {
-	server.Lock()
-	info := server.info
-	server.Unlock()
-	return info
-}
-
-func (server *mongoServer) hasTags(serverTags []bson.D) bool {
-NextTagSet:
-	for _, tags := range serverTags {
-	NextReqTag:
-		for _, req := range tags {
-			for _, has := range server.info.Tags {
-				if req.Name == has.Name {
-					if req.Value == has.Value {
-						continue NextReqTag
-					}
-					continue NextTagSet
-				}
-			}
-			continue NextTagSet
-		}
-		return true
-	}
-	return false
-}
-
-var pingDelay = 15 * time.Second
-
-func (server *mongoServer) pinger(loop bool) {
-	var delay time.Duration
-	if raceDetector {
-		// This variable is only ever touched by tests.
-		globalMutex.Lock()
-		delay = pingDelay
-		globalMutex.Unlock()
-	} else {
-		delay = pingDelay
-	}
-	op := queryOp{
-		collection: "admin.$cmd",
-		query:      bson.D{{"ping", 1}},
-		flags:      flagSlaveOk,
-		limit:      -1,
-	}
-	for {
-		if loop {
-			time.Sleep(delay)
-		}
-		op := op
-		socket, _, err := server.AcquireSocket(0, delay)
-		if err == nil {
-			start := time.Now()
-			_, _ = socket.SimpleQuery(&op)
-			delay := time.Now().Sub(start)
-
-			server.pingWindow[server.pingIndex] = delay
-			server.pingIndex = (server.pingIndex + 1) % len(server.pingWindow)
-			server.pingCount++
-			var max time.Duration
-			for i := 0; i < len(server.pingWindow) && uint32(i) < server.pingCount; i++ {
-				if server.pingWindow[i] > max {
-					max = server.pingWindow[i]
-				}
-			}
-			socket.Release()
-			server.Lock()
-			if server.closed {
-				loop = false
-			}
-			server.pingValue = max
-			server.Unlock()
-			logf("Ping for %s is %d ms", server.Addr, max/time.Millisecond)
-		} else if err == errServerClosed {
-			return
-		}
-		if !loop {
-			return
-		}
-	}
-}
-
-type mongoServerSlice []*mongoServer
-
-func (s mongoServerSlice) Len() int {
-	return len(s)
-}
-
-func (s mongoServerSlice) Less(i, j int) bool {
-	return s[i].ResolvedAddr < s[j].ResolvedAddr
-}
-
-func (s mongoServerSlice) Swap(i, j int) {
-	s[i], s[j] = s[j], s[i]
-}
-
-func (s mongoServerSlice) Sort() {
-	sort.Sort(s)
-}
-
-func (s mongoServerSlice) Search(resolvedAddr string) (i int, ok bool) {
-	n := len(s)
-	i = sort.Search(n, func(i int) bool {
-		return s[i].ResolvedAddr >= resolvedAddr
-	})
-	return i, i != n && s[i].ResolvedAddr == resolvedAddr
-}
-
-type mongoServers struct {
-	slice mongoServerSlice
-}
-
-func (servers *mongoServers) Search(resolvedAddr string) (server *mongoServer) {
-	if i, ok := servers.slice.Search(resolvedAddr); ok {
-		return servers.slice[i]
-	}
-	return nil
-}
-
-func (servers *mongoServers) Add(server *mongoServer) {
-	servers.slice = append(servers.slice, server)
-	servers.slice.Sort()
-}
-
-func (servers *mongoServers) Remove(other *mongoServer) (server *mongoServer) {
-	if i, found := servers.slice.Search(other.ResolvedAddr); found {
-		server = servers.slice[i]
-		copy(servers.slice[i:], servers.slice[i+1:])
-		n := len(servers.slice) - 1
-		servers.slice[n] = nil // Help GC.
-		servers.slice = servers.slice[:n]
-	}
-	return
-}
-
-func (servers *mongoServers) Slice() []*mongoServer {
-	return ([]*mongoServer)(servers.slice)
-}
-
-func (servers *mongoServers) Get(i int) *mongoServer {
-	return servers.slice[i]
-}
-
-func (servers *mongoServers) Len() int {
-	return len(servers.slice)
-}
-
-func (servers *mongoServers) Empty() bool {
-	return len(servers.slice) == 0
-}
-
-func (servers *mongoServers) HasMongos() bool {
-	for _, s := range servers.slice {
-		if s.Info().Mongos {
-			return true
-		}
-	}
-	return false
-}
-
-// BestFit returns the best guess of what would be the most interesting
-// server to perform operations on at this point in time.
-func (servers *mongoServers) BestFit(mode Mode, serverTags []bson.D) *mongoServer {
-	var best *mongoServer
-	for _, next := range servers.slice {
-		if best == nil {
-			best = next
-			best.RLock()
-			if serverTags != nil && !next.info.Mongos && !best.hasTags(serverTags) {
-				best.RUnlock()
-				best = nil
-			}
-			continue
-		}
-		next.RLock()
-		swap := false
-		switch {
-		case serverTags != nil && !next.info.Mongos && !next.hasTags(serverTags):
-			// Must have requested tags.
-		case mode == Secondary && next.info.Master && !next.info.Mongos:
-			// Must be a secondary or mongos.
-		case next.info.Master != best.info.Master && mode != Nearest:
-			// Prefer slaves, unless the mode is PrimaryPreferred.
-			swap = (mode == PrimaryPreferred) != best.info.Master
-		case absDuration(next.pingValue-best.pingValue) > 15*time.Millisecond:
-			// Prefer nearest server.
-			swap = next.pingValue < best.pingValue
-		case len(next.liveSockets)-len(next.unusedSockets) < len(best.liveSockets)-len(best.unusedSockets):
-			// Prefer servers with less connections.
-			swap = true
-		}
-		if swap {
-			best.RUnlock()
-			best = next
-		} else {
-			next.RUnlock()
-		}
-	}
-	if best != nil {
-		best.RUnlock()
-	}
-	return best
-}
-
-func absDuration(d time.Duration) time.Duration {
-	if d < 0 {
-		return -d
-	}
-	return d
-}
diff --git a/vendor/gopkg.in/mgo.v2/session.go b/vendor/gopkg.in/mgo.v2/session.go
deleted file mode 100644
index 3dccf36..0000000
--- a/vendor/gopkg.in/mgo.v2/session.go
+++ /dev/null
@@ -1,4825 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"crypto/md5"
-	"encoding/hex"
-	"errors"
-	"fmt"
-	"math"
-	"net"
-	"net/url"
-	"reflect"
-	"sort"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"gopkg.in/mgo.v2/bson"
-)
-
-type Mode int
-
-const (
-	// Relevant documentation on read preference modes:
-	//
-	//     http://docs.mongodb.org/manual/reference/read-preference/
-	//
-	Primary            Mode = 2 // Default mode. All operations read from the current replica set primary.
-	PrimaryPreferred   Mode = 3 // Read from the primary if available. Read from the secondary otherwise.
-	Secondary          Mode = 4 // Read from one of the nearest secondary members of the replica set.
-	SecondaryPreferred Mode = 5 // Read from one of the nearest secondaries if available. Read from primary otherwise.
-	Nearest            Mode = 6 // Read from one of the nearest members, irrespective of it being primary or secondary.
-
-	// Read preference modes are specific to mgo:
-	Eventual  Mode = 0 // Same as Nearest, but may change servers between reads.
-	Monotonic Mode = 1 // Same as SecondaryPreferred before first write. Same as Primary after first write.
-	Strong    Mode = 2 // Same as Primary.
-)
-
-// mgo.v3: Drop Strong mode, suffix all modes with "Mode".
-
-// When changing the Session type, check if newSession and copySession
-// need to be updated too.
-
-// Session represents a communication session with the database.
-//
-// All Session methods are concurrency-safe and may be called from multiple
-// goroutines. In all session modes but Eventual, using the session from
-// multiple goroutines will cause them to share the same underlying socket.
-// See the documentation on Session.SetMode for more details.
-type Session struct {
-	m                sync.RWMutex
-	cluster_         *mongoCluster
-	slaveSocket      *mongoSocket
-	masterSocket     *mongoSocket
-	slaveOk          bool
-	consistency      Mode
-	queryConfig      query
-	safeOp           *queryOp
-	syncTimeout      time.Duration
-	sockTimeout      time.Duration
-	defaultdb        string
-	sourcedb         string
-	dialCred         *Credential
-	creds            []Credential
-	poolLimit        int
-	bypassValidation bool
-}
-
-type Database struct {
-	Session *Session
-	Name    string
-}
-
-type Collection struct {
-	Database *Database
-	Name     string // "collection"
-	FullName string // "db.collection"
-}
-
-type Query struct {
-	m       sync.Mutex
-	session *Session
-	query   // Enables default settings in session.
-}
-
-type query struct {
-	op       queryOp
-	prefetch float64
-	limit    int32
-}
-
-type getLastError struct {
-	CmdName  int         "getLastError,omitempty"
-	W        interface{} "w,omitempty"
-	WTimeout int         "wtimeout,omitempty"
-	FSync    bool        "fsync,omitempty"
-	J        bool        "j,omitempty"
-}
-
-type Iter struct {
-	m              sync.Mutex
-	gotReply       sync.Cond
-	session        *Session
-	server         *mongoServer
-	docData        queue
-	err            error
-	op             getMoreOp
-	prefetch       float64
-	limit          int32
-	docsToReceive  int
-	docsBeforeMore int
-	timeout        time.Duration
-	timedout       bool
-	findCmd        bool
-}
-
-var (
-	ErrNotFound = errors.New("not found")
-	ErrCursor   = errors.New("invalid cursor")
-)
-
-const (
-	defaultPrefetch  = 0.25
-	maxUpsertRetries = 5
-)
-
-// Dial establishes a new session to the cluster identified by the given seed
-// server(s). The session will enable communication with all of the servers in
-// the cluster, so the seed servers are used only to find out about the cluster
-// topology.
-//
-// Dial will timeout after 10 seconds if a server isn't reached. The returned
-// session will timeout operations after one minute by default if servers
-// aren't available. To customize the timeout, see DialWithTimeout,
-// SetSyncTimeout, and SetSocketTimeout.
-//
-// This method is generally called just once for a given cluster.  Further
-// sessions to the same cluster are then established using the New or Copy
-// methods on the obtained session. This will make them share the underlying
-// cluster, and manage the pool of connections appropriately.
-//
-// Once the session is not useful anymore, Close must be called to release the
-// resources appropriately.
-//
-// The seed servers must be provided in the following format:
-//
-//     [mongodb://][user:pass@]host1[:port1][,host2[:port2],...][/database][?options]
-//
-// For example, it may be as simple as:
-//
-//     localhost
-//
-// Or more involved like:
-//
-//     mongodb://myuser:mypass@localhost:40001,otherhost:40001/mydb
-//
-// If the port number is not provided for a server, it defaults to 27017.
-//
-// The username and password provided in the URL will be used to authenticate
-// into the database named after the slash at the end of the host names, or
-// into the "admin" database if none is provided.  The authentication information
-// will persist in sessions obtained through the New method as well.
-//
-// The following connection options are supported after the question mark:
-//
-//     connect=direct
-//
-//         Disables the automatic replica set server discovery logic, and
-//         forces the use of servers provided only (even if secondaries).
-//         Note that to talk to a secondary the consistency requirements
-//         must be relaxed to Monotonic or Eventual via SetMode.
-//
-//
-//     connect=replicaSet
-//
-//  	   Discover replica sets automatically. Default connection behavior.
-//
-//
-//     replicaSet=<setname>
-//
-//         If specified will prevent the obtained session from communicating
-//         with any server which is not part of a replica set with the given name.
-//         The default is to communicate with any server specified or discovered
-//         via the servers contacted.
-//
-//
-//     authSource=<db>
-//
-//         Informs the database used to establish credentials and privileges
-//         with a MongoDB server. Defaults to the database name provided via
-//         the URL path, and "admin" if that's unset.
-//
-//
-//     authMechanism=<mechanism>
-//
-//        Defines the protocol for credential negotiation. Defaults to "MONGODB-CR",
-//        which is the default username/password challenge-response mechanism.
-//
-//
-//     gssapiServiceName=<name>
-//
-//        Defines the service name to use when authenticating with the GSSAPI
-//        mechanism. Defaults to "mongodb".
-//
-//
-//     maxPoolSize=<limit>
-//
-//        Defines the per-server socket pool limit. Defaults to 4096.
-//        See Session.SetPoolLimit for details.
-//
-//
-// Relevant documentation:
-//
-//     http://docs.mongodb.org/manual/reference/connection-string/
-//
-func Dial(url string) (*Session, error) {
-	session, err := DialWithTimeout(url, 10*time.Second)
-	if err == nil {
-		session.SetSyncTimeout(1 * time.Minute)
-		session.SetSocketTimeout(1 * time.Minute)
-	}
-	return session, err
-}
-
-// DialWithTimeout works like Dial, but uses timeout as the amount of time to
-// wait for a server to respond when first connecting and also on follow up
-// operations in the session. If timeout is zero, the call may block
-// forever waiting for a connection to be made.
-//
-// See SetSyncTimeout for customizing the timeout for the session.
-func DialWithTimeout(url string, timeout time.Duration) (*Session, error) {
-	info, err := ParseURL(url)
-	if err != nil {
-		return nil, err
-	}
-	info.Timeout = timeout
-	return DialWithInfo(info)
-}
-
-// ParseURL parses a MongoDB URL as accepted by the Dial function and returns
-// a value suitable for providing into DialWithInfo.
-//
-// See Dial for more details on the format of url.
-func ParseURL(url string) (*DialInfo, error) {
-	uinfo, err := extractURL(url)
-	if err != nil {
-		return nil, err
-	}
-	direct := false
-	mechanism := ""
-	service := ""
-	source := ""
-	setName := ""
-	poolLimit := 0
-	for k, v := range uinfo.options {
-		switch k {
-		case "authSource":
-			source = v
-		case "authMechanism":
-			mechanism = v
-		case "gssapiServiceName":
-			service = v
-		case "replicaSet":
-			setName = v
-		case "maxPoolSize":
-			poolLimit, err = strconv.Atoi(v)
-			if err != nil {
-				return nil, errors.New("bad value for maxPoolSize: " + v)
-			}
-		case "connect":
-			if v == "direct" {
-				direct = true
-				break
-			}
-			if v == "replicaSet" {
-				break
-			}
-			fallthrough
-		default:
-			return nil, errors.New("unsupported connection URL option: " + k + "=" + v)
-		}
-	}
-	info := DialInfo{
-		Addrs:          uinfo.addrs,
-		Direct:         direct,
-		Database:       uinfo.db,
-		Username:       uinfo.user,
-		Password:       uinfo.pass,
-		Mechanism:      mechanism,
-		Service:        service,
-		Source:         source,
-		PoolLimit:      poolLimit,
-		ReplicaSetName: setName,
-	}
-	return &info, nil
-}
-
-// DialInfo holds options for establishing a session with a MongoDB cluster.
-// To use a URL, see the Dial function.
-type DialInfo struct {
-	// Addrs holds the addresses for the seed servers.
-	Addrs []string
-
-	// Direct informs whether to establish connections only with the
-	// specified seed servers, or to obtain information for the whole
-	// cluster and establish connections with further servers too.
-	Direct bool
-
-	// Timeout is the amount of time to wait for a server to respond when
-	// first connecting and on follow up operations in the session. If
-	// timeout is zero, the call may block forever waiting for a connection
-	// to be established. Timeout does not affect logic in DialServer.
-	Timeout time.Duration
-
-	// FailFast will cause connection and query attempts to fail faster when
-	// the server is unavailable, instead of retrying until the configured
-	// timeout period. Note that an unavailable server may silently drop
-	// packets instead of rejecting them, in which case it's impossible to
-	// distinguish it from a slow server, so the timeout stays relevant.
-	FailFast bool
-
-	// Database is the default database name used when the Session.DB method
-	// is called with an empty name, and is also used during the initial
-	// authentication if Source is unset.
-	Database string
-
-	// ReplicaSetName, if specified, will prevent the obtained session from
-	// communicating with any server which is not part of a replica set
-	// with the given name. The default is to communicate with any server
-	// specified or discovered via the servers contacted.
-	ReplicaSetName string
-
-	// Source is the database used to establish credentials and privileges
-	// with a MongoDB server. Defaults to the value of Database, if that is
-	// set, or "admin" otherwise.
-	Source string
-
-	// Service defines the service name to use when authenticating with the GSSAPI
-	// mechanism. Defaults to "mongodb".
-	Service string
-
-	// ServiceHost defines which hostname to use when authenticating
-	// with the GSSAPI mechanism. If not specified, defaults to the MongoDB
-	// server's address.
-	ServiceHost string
-
-	// Mechanism defines the protocol for credential negotiation.
-	// Defaults to "MONGODB-CR".
-	Mechanism string
-
-	// Username and Password inform the credentials for the initial authentication
-	// done on the database defined by the Source field. See Session.Login.
-	Username string
-	Password string
-
-	// PoolLimit defines the per-server socket pool limit. Defaults to 4096.
-	// See Session.SetPoolLimit for details.
-	PoolLimit int
-
-	// DialServer optionally specifies the dial function for establishing
-	// connections with the MongoDB servers.
-	DialServer func(addr *ServerAddr) (net.Conn, error)
-
-	// WARNING: This field is obsolete. See DialServer above.
-	Dial func(addr net.Addr) (net.Conn, error)
-}
-
-// mgo.v3: Drop DialInfo.Dial.
-
-// ServerAddr represents the address for establishing a connection to an
-// individual MongoDB server.
-type ServerAddr struct {
-	str string
-	tcp *net.TCPAddr
-}
-
-// String returns the address that was provided for the server before resolution.
-func (addr *ServerAddr) String() string {
-	return addr.str
-}
-
-// TCPAddr returns the resolved TCP address for the server.
-func (addr *ServerAddr) TCPAddr() *net.TCPAddr {
-	return addr.tcp
-}
-
-// DialWithInfo establishes a new session to the cluster identified by info.
-func DialWithInfo(info *DialInfo) (*Session, error) {
-	addrs := make([]string, len(info.Addrs))
-	for i, addr := range info.Addrs {
-		p := strings.LastIndexAny(addr, "]:")
-		if p == -1 || addr[p] != ':' {
-			// XXX This is untested. The test suite doesn't use the standard port.
-			addr += ":27017"
-		}
-		addrs[i] = addr
-	}
-	cluster := newCluster(addrs, info.Direct, info.FailFast, dialer{info.Dial, info.DialServer}, info.ReplicaSetName)
-	session := newSession(Eventual, cluster, info.Timeout)
-	session.defaultdb = info.Database
-	if session.defaultdb == "" {
-		session.defaultdb = "test"
-	}
-	session.sourcedb = info.Source
-	if session.sourcedb == "" {
-		session.sourcedb = info.Database
-		if session.sourcedb == "" {
-			session.sourcedb = "admin"
-		}
-	}
-	if info.Username != "" {
-		source := session.sourcedb
-		if info.Source == "" &&
-			(info.Mechanism == "GSSAPI" || info.Mechanism == "PLAIN" || info.Mechanism == "MONGODB-X509") {
-			source = "$external"
-		}
-		session.dialCred = &Credential{
-			Username:    info.Username,
-			Password:    info.Password,
-			Mechanism:   info.Mechanism,
-			Service:     info.Service,
-			ServiceHost: info.ServiceHost,
-			Source:      source,
-		}
-		session.creds = []Credential{*session.dialCred}
-	}
-	if info.PoolLimit > 0 {
-		session.poolLimit = info.PoolLimit
-	}
-	cluster.Release()
-
-	// People get confused when we return a session that is not actually
-	// established to any servers yet (e.g. what if url was wrong). So,
-	// ping the server to ensure there's someone there, and abort if it
-	// fails.
-	if err := session.Ping(); err != nil {
-		session.Close()
-		return nil, err
-	}
-	session.SetMode(Strong, true)
-	return session, nil
-}
-
-func isOptSep(c rune) bool {
-	return c == ';' || c == '&'
-}
-
-type urlInfo struct {
-	addrs   []string
-	user    string
-	pass    string
-	db      string
-	options map[string]string
-}
-
-func extractURL(s string) (*urlInfo, error) {
-	if strings.HasPrefix(s, "mongodb://") {
-		s = s[10:]
-	}
-	info := &urlInfo{options: make(map[string]string)}
-	if c := strings.Index(s, "?"); c != -1 {
-		for _, pair := range strings.FieldsFunc(s[c+1:], isOptSep) {
-			l := strings.SplitN(pair, "=", 2)
-			if len(l) != 2 || l[0] == "" || l[1] == "" {
-				return nil, errors.New("connection option must be key=value: " + pair)
-			}
-			info.options[l[0]] = l[1]
-		}
-		s = s[:c]
-	}
-	if c := strings.Index(s, "@"); c != -1 {
-		pair := strings.SplitN(s[:c], ":", 2)
-		if len(pair) > 2 || pair[0] == "" {
-			return nil, errors.New("credentials must be provided as user:pass@host")
-		}
-		var err error
-		info.user, err = url.QueryUnescape(pair[0])
-		if err != nil {
-			return nil, fmt.Errorf("cannot unescape username in URL: %q", pair[0])
-		}
-		if len(pair) > 1 {
-			info.pass, err = url.QueryUnescape(pair[1])
-			if err != nil {
-				return nil, fmt.Errorf("cannot unescape password in URL")
-			}
-		}
-		s = s[c+1:]
-	}
-	if c := strings.Index(s, "/"); c != -1 {
-		info.db = s[c+1:]
-		s = s[:c]
-	}
-	info.addrs = strings.Split(s, ",")
-	return info, nil
-}
-
-func newSession(consistency Mode, cluster *mongoCluster, timeout time.Duration) (session *Session) {
-	cluster.Acquire()
-	session = &Session{
-		cluster_:    cluster,
-		syncTimeout: timeout,
-		sockTimeout: timeout,
-		poolLimit:   4096,
-	}
-	debugf("New session %p on cluster %p", session, cluster)
-	session.SetMode(consistency, true)
-	session.SetSafe(&Safe{})
-	session.queryConfig.prefetch = defaultPrefetch
-	return session
-}
-
-func copySession(session *Session, keepCreds bool) (s *Session) {
-	cluster := session.cluster()
-	cluster.Acquire()
-	if session.masterSocket != nil {
-		session.masterSocket.Acquire()
-	}
-	if session.slaveSocket != nil {
-		session.slaveSocket.Acquire()
-	}
-	var creds []Credential
-	if keepCreds {
-		creds = make([]Credential, len(session.creds))
-		copy(creds, session.creds)
-	} else if session.dialCred != nil {
-		creds = []Credential{*session.dialCred}
-	}
-	scopy := *session
-	scopy.m = sync.RWMutex{}
-	scopy.creds = creds
-	s = &scopy
-	debugf("New session %p on cluster %p (copy from %p)", s, cluster, session)
-	return s
-}
-
-// LiveServers returns a list of server addresses which are
-// currently known to be alive.
-func (s *Session) LiveServers() (addrs []string) {
-	s.m.RLock()
-	addrs = s.cluster().LiveServers()
-	s.m.RUnlock()
-	return addrs
-}
-
-// DB returns a value representing the named database. If name
-// is empty, the database name provided in the dialed URL is
-// used instead. If that is also empty, "test" is used as a
-// fallback in a way equivalent to the mongo shell.
-//
-// Creating this value is a very lightweight operation, and
-// involves no network communication.
-func (s *Session) DB(name string) *Database {
-	if name == "" {
-		name = s.defaultdb
-	}
-	return &Database{s, name}
-}
-
-// C returns a value representing the named collection.
-//
-// Creating this value is a very lightweight operation, and
-// involves no network communication.
-func (db *Database) C(name string) *Collection {
-	return &Collection{db, name, db.Name + "." + name}
-}
-
-// With returns a copy of db that uses session s.
-func (db *Database) With(s *Session) *Database {
-	newdb := *db
-	newdb.Session = s
-	return &newdb
-}
-
-// With returns a copy of c that uses session s.
-func (c *Collection) With(s *Session) *Collection {
-	newdb := *c.Database
-	newdb.Session = s
-	newc := *c
-	newc.Database = &newdb
-	return &newc
-}
-
-// GridFS returns a GridFS value representing collections in db that
-// follow the standard GridFS specification.
-// The provided prefix (sometimes known as root) will determine which
-// collections to use, and is usually set to "fs" when there is a
-// single GridFS in the database.
-//
-// See the GridFS Create, Open, and OpenId methods for more details.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/GridFS
-//     http://www.mongodb.org/display/DOCS/GridFS+Tools
-//     http://www.mongodb.org/display/DOCS/GridFS+Specification
-//
-func (db *Database) GridFS(prefix string) *GridFS {
-	return newGridFS(db, prefix)
-}
-
-// Run issues the provided command on the db database and unmarshals
-// its result in the respective argument. The cmd argument may be either
-// a string with the command name itself, in which case an empty document of
-// the form bson.M{cmd: 1} will be used, or it may be a full command document.
-//
-// Note that MongoDB considers the first marshalled key as the command
-// name, so when providing a command with options, it's important to
-// use an ordering-preserving document, such as a struct value or an
-// instance of bson.D.  For instance:
-//
-//     db.Run(bson.D{{"create", "mycollection"}, {"size", 1024}})
-//
-// For privilleged commands typically run on the "admin" database, see
-// the Run method in the Session type.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Commands
-//     http://www.mongodb.org/display/DOCS/List+of+Database+CommandSkips
-//
-func (db *Database) Run(cmd interface{}, result interface{}) error {
-	socket, err := db.Session.acquireSocket(true)
-	if err != nil {
-		return err
-	}
-	defer socket.Release()
-
-	// This is an optimized form of db.C("$cmd").Find(cmd).One(result).
-	return db.run(socket, cmd, result)
-}
-
-// Credential holds details to authenticate with a MongoDB server.
-type Credential struct {
-	// Username and Password hold the basic details for authentication.
-	// Password is optional with some authentication mechanisms.
-	Username string
-	Password string
-
-	// Source is the database used to establish credentials and privileges
-	// with a MongoDB server. Defaults to the default database provided
-	// during dial, or "admin" if that was unset.
-	Source string
-
-	// Service defines the service name to use when authenticating with the GSSAPI
-	// mechanism. Defaults to "mongodb".
-	Service string
-
-	// ServiceHost defines which hostname to use when authenticating
-	// with the GSSAPI mechanism. If not specified, defaults to the MongoDB
-	// server's address.
-	ServiceHost string
-
-	// Mechanism defines the protocol for credential negotiation.
-	// Defaults to "MONGODB-CR".
-	Mechanism string
-}
-
-// Login authenticates with MongoDB using the provided credential.  The
-// authentication is valid for the whole session and will stay valid until
-// Logout is explicitly called for the same database, or the session is
-// closed.
-func (db *Database) Login(user, pass string) error {
-	return db.Session.Login(&Credential{Username: user, Password: pass, Source: db.Name})
-}
-
-// Login authenticates with MongoDB using the provided credential.  The
-// authentication is valid for the whole session and will stay valid until
-// Logout is explicitly called for the same database, or the session is
-// closed.
-func (s *Session) Login(cred *Credential) error {
-	socket, err := s.acquireSocket(true)
-	if err != nil {
-		return err
-	}
-	defer socket.Release()
-
-	credCopy := *cred
-	if cred.Source == "" {
-		if cred.Mechanism == "GSSAPI" {
-			credCopy.Source = "$external"
-		} else {
-			credCopy.Source = s.sourcedb
-		}
-	}
-	err = socket.Login(credCopy)
-	if err != nil {
-		return err
-	}
-
-	s.m.Lock()
-	s.creds = append(s.creds, credCopy)
-	s.m.Unlock()
-	return nil
-}
-
-func (s *Session) socketLogin(socket *mongoSocket) error {
-	for _, cred := range s.creds {
-		if err := socket.Login(cred); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// Logout removes any established authentication credentials for the database.
-func (db *Database) Logout() {
-	session := db.Session
-	dbname := db.Name
-	session.m.Lock()
-	found := false
-	for i, cred := range session.creds {
-		if cred.Source == dbname {
-			copy(session.creds[i:], session.creds[i+1:])
-			session.creds = session.creds[:len(session.creds)-1]
-			found = true
-			break
-		}
-	}
-	if found {
-		if session.masterSocket != nil {
-			session.masterSocket.Logout(dbname)
-		}
-		if session.slaveSocket != nil {
-			session.slaveSocket.Logout(dbname)
-		}
-	}
-	session.m.Unlock()
-}
-
-// LogoutAll removes all established authentication credentials for the session.
-func (s *Session) LogoutAll() {
-	s.m.Lock()
-	for _, cred := range s.creds {
-		if s.masterSocket != nil {
-			s.masterSocket.Logout(cred.Source)
-		}
-		if s.slaveSocket != nil {
-			s.slaveSocket.Logout(cred.Source)
-		}
-	}
-	s.creds = s.creds[0:0]
-	s.m.Unlock()
-}
-
-// User represents a MongoDB user.
-//
-// Relevant documentation:
-//
-//     http://docs.mongodb.org/manual/reference/privilege-documents/
-//     http://docs.mongodb.org/manual/reference/user-privileges/
-//
-type User struct {
-	// Username is how the user identifies itself to the system.
-	Username string `bson:"user"`
-
-	// Password is the plaintext password for the user. If set,
-	// the UpsertUser method will hash it into PasswordHash and
-	// unset it before the user is added to the database.
-	Password string `bson:",omitempty"`
-
-	// PasswordHash is the MD5 hash of Username+":mongo:"+Password.
-	PasswordHash string `bson:"pwd,omitempty"`
-
-	// CustomData holds arbitrary data admins decide to associate
-	// with this user, such as the full name or employee id.
-	CustomData interface{} `bson:"customData,omitempty"`
-
-	// Roles indicates the set of roles the user will be provided.
-	// See the Role constants.
-	Roles []Role `bson:"roles"`
-
-	// OtherDBRoles allows assigning roles in other databases from
-	// user documents inserted in the admin database. This field
-	// only works in the admin database.
-	OtherDBRoles map[string][]Role `bson:"otherDBRoles,omitempty"`
-
-	// UserSource indicates where to look for this user's credentials.
-	// It may be set to a database name, or to "$external" for
-	// consulting an external resource such as Kerberos. UserSource
-	// must not be set if Password or PasswordHash are present.
-	//
-	// WARNING: This setting was only ever supported in MongoDB 2.4,
-	// and is now obsolete.
-	UserSource string `bson:"userSource,omitempty"`
-}
-
-type Role string
-
-const (
-	// Relevant documentation:
-	//
-	//     http://docs.mongodb.org/manual/reference/user-privileges/
-	//
-	RoleRoot         Role = "root"
-	RoleRead         Role = "read"
-	RoleReadAny      Role = "readAnyDatabase"
-	RoleReadWrite    Role = "readWrite"
-	RoleReadWriteAny Role = "readWriteAnyDatabase"
-	RoleDBAdmin      Role = "dbAdmin"
-	RoleDBAdminAny   Role = "dbAdminAnyDatabase"
-	RoleUserAdmin    Role = "userAdmin"
-	RoleUserAdminAny Role = "userAdminAnyDatabase"
-	RoleClusterAdmin Role = "clusterAdmin"
-)
-
-// UpsertUser updates the authentication credentials and the roles for
-// a MongoDB user within the db database. If the named user doesn't exist
-// it will be created.
-//
-// This method should only be used from MongoDB 2.4 and on. For older
-// MongoDB releases, use the obsolete AddUser method instead.
-//
-// Relevant documentation:
-//
-//     http://docs.mongodb.org/manual/reference/user-privileges/
-//     http://docs.mongodb.org/manual/reference/privilege-documents/
-//
-func (db *Database) UpsertUser(user *User) error {
-	if user.Username == "" {
-		return fmt.Errorf("user has no Username")
-	}
-	if (user.Password != "" || user.PasswordHash != "") && user.UserSource != "" {
-		return fmt.Errorf("user has both Password/PasswordHash and UserSource set")
-	}
-	if len(user.OtherDBRoles) > 0 && db.Name != "admin" && db.Name != "$external" {
-		return fmt.Errorf("user with OtherDBRoles is only supported in the admin or $external databases")
-	}
-
-	// Attempt to run this using 2.6+ commands.
-	rundb := db
-	if user.UserSource != "" {
-		// Compatibility logic for the userSource field of MongoDB <= 2.4.X
-		rundb = db.Session.DB(user.UserSource)
-	}
-	err := rundb.runUserCmd("updateUser", user)
-	// retry with createUser when isAuthError in order to enable the "localhost exception"
-	if isNotFound(err) || isAuthError(err) {
-		return rundb.runUserCmd("createUser", user)
-	}
-	if !isNoCmd(err) {
-		return err
-	}
-
-	// Command does not exist. Fallback to pre-2.6 behavior.
-	var set, unset bson.D
-	if user.Password != "" {
-		psum := md5.New()
-		psum.Write([]byte(user.Username + ":mongo:" + user.Password))
-		set = append(set, bson.DocElem{"pwd", hex.EncodeToString(psum.Sum(nil))})
-		unset = append(unset, bson.DocElem{"userSource", 1})
-	} else if user.PasswordHash != "" {
-		set = append(set, bson.DocElem{"pwd", user.PasswordHash})
-		unset = append(unset, bson.DocElem{"userSource", 1})
-	}
-	if user.UserSource != "" {
-		set = append(set, bson.DocElem{"userSource", user.UserSource})
-		unset = append(unset, bson.DocElem{"pwd", 1})
-	}
-	if user.Roles != nil || user.OtherDBRoles != nil {
-		set = append(set, bson.DocElem{"roles", user.Roles})
-		if len(user.OtherDBRoles) > 0 {
-			set = append(set, bson.DocElem{"otherDBRoles", user.OtherDBRoles})
-		} else {
-			unset = append(unset, bson.DocElem{"otherDBRoles", 1})
-		}
-	}
-	users := db.C("system.users")
-	err = users.Update(bson.D{{"user", user.Username}}, bson.D{{"$unset", unset}, {"$set", set}})
-	if err == ErrNotFound {
-		set = append(set, bson.DocElem{"user", user.Username})
-		if user.Roles == nil && user.OtherDBRoles == nil {
-			// Roles must be sent, as it's the way MongoDB distinguishes
-			// old-style documents from new-style documents in pre-2.6.
-			set = append(set, bson.DocElem{"roles", user.Roles})
-		}
-		err = users.Insert(set)
-	}
-	return err
-}
-
-func isNoCmd(err error) bool {
-	e, ok := err.(*QueryError)
-	return ok && (e.Code == 59 || e.Code == 13390 || strings.HasPrefix(e.Message, "no such cmd:"))
-}
-
-func isNotFound(err error) bool {
-	e, ok := err.(*QueryError)
-	return ok && e.Code == 11
-}
-
-func isAuthError(err error) bool {
-	e, ok := err.(*QueryError)
-	return ok && e.Code == 13
-}
-
-func (db *Database) runUserCmd(cmdName string, user *User) error {
-	cmd := make(bson.D, 0, 16)
-	cmd = append(cmd, bson.DocElem{cmdName, user.Username})
-	if user.Password != "" {
-		cmd = append(cmd, bson.DocElem{"pwd", user.Password})
-	}
-	var roles []interface{}
-	for _, role := range user.Roles {
-		roles = append(roles, role)
-	}
-	for db, dbroles := range user.OtherDBRoles {
-		for _, role := range dbroles {
-			roles = append(roles, bson.D{{"role", role}, {"db", db}})
-		}
-	}
-	if roles != nil || user.Roles != nil || cmdName == "createUser" {
-		cmd = append(cmd, bson.DocElem{"roles", roles})
-	}
-	err := db.Run(cmd, nil)
-	if !isNoCmd(err) && user.UserSource != "" && (user.UserSource != "$external" || db.Name != "$external") {
-		return fmt.Errorf("MongoDB 2.6+ does not support the UserSource setting")
-	}
-	return err
-}
-
-// AddUser creates or updates the authentication credentials of user within
-// the db database.
-//
-// WARNING: This method is obsolete and should only be used with MongoDB 2.2
-// or earlier. For MongoDB 2.4 and on, use UpsertUser instead.
-func (db *Database) AddUser(username, password string, readOnly bool) error {
-	// Try to emulate the old behavior on 2.6+
-	user := &User{Username: username, Password: password}
-	if db.Name == "admin" {
-		if readOnly {
-			user.Roles = []Role{RoleReadAny}
-		} else {
-			user.Roles = []Role{RoleReadWriteAny}
-		}
-	} else {
-		if readOnly {
-			user.Roles = []Role{RoleRead}
-		} else {
-			user.Roles = []Role{RoleReadWrite}
-		}
-	}
-	err := db.runUserCmd("updateUser", user)
-	if isNotFound(err) {
-		return db.runUserCmd("createUser", user)
-	}
-	if !isNoCmd(err) {
-		return err
-	}
-
-	// Command doesn't exist. Fallback to pre-2.6 behavior.
-	psum := md5.New()
-	psum.Write([]byte(username + ":mongo:" + password))
-	digest := hex.EncodeToString(psum.Sum(nil))
-	c := db.C("system.users")
-	_, err = c.Upsert(bson.M{"user": username}, bson.M{"$set": bson.M{"user": username, "pwd": digest, "readOnly": readOnly}})
-	return err
-}
-
-// RemoveUser removes the authentication credentials of user from the database.
-func (db *Database) RemoveUser(user string) error {
-	err := db.Run(bson.D{{"dropUser", user}}, nil)
-	if isNoCmd(err) {
-		users := db.C("system.users")
-		return users.Remove(bson.M{"user": user})
-	}
-	if isNotFound(err) {
-		return ErrNotFound
-	}
-	return err
-}
-
-type indexSpec struct {
-	Name, NS         string
-	Key              bson.D
-	Unique           bool    ",omitempty"
-	DropDups         bool    "dropDups,omitempty"
-	Background       bool    ",omitempty"
-	Sparse           bool    ",omitempty"
-	Bits             int     ",omitempty"
-	Min, Max         float64 ",omitempty"
-	BucketSize       float64 "bucketSize,omitempty"
-	ExpireAfter      int     "expireAfterSeconds,omitempty"
-	Weights          bson.D  ",omitempty"
-	DefaultLanguage  string  "default_language,omitempty"
-	LanguageOverride string  "language_override,omitempty"
-	TextIndexVersion int     "textIndexVersion,omitempty"
-
-	Collation *Collation "collation,omitempty"
-}
-
-type Index struct {
-	Key        []string // Index key fields; prefix name with dash (-) for descending order
-	Unique     bool     // Prevent two documents from having the same index key
-	DropDups   bool     // Drop documents with the same index key as a previously indexed one
-	Background bool     // Build index in background and return immediately
-	Sparse     bool     // Only index documents containing the Key fields
-
-	// If ExpireAfter is defined the server will periodically delete
-	// documents with indexed time.Time older than the provided delta.
-	ExpireAfter time.Duration
-
-	// Name holds the stored index name. On creation if this field is unset it is
-	// computed by EnsureIndex based on the index key.
-	Name string
-
-	// Properties for spatial indexes.
-	//
-	// Min and Max were improperly typed as int when they should have been
-	// floats.  To preserve backwards compatibility they are still typed as
-	// int and the following two fields enable reading and writing the same
-	// fields as float numbers. In mgo.v3, these fields will be dropped and
-	// Min/Max will become floats.
-	Min, Max   int
-	Minf, Maxf float64
-	BucketSize float64
-	Bits       int
-
-	// Properties for text indexes.
-	DefaultLanguage  string
-	LanguageOverride string
-
-	// Weights defines the significance of provided fields relative to other
-	// fields in a text index. The score for a given word in a document is derived
-	// from the weighted sum of the frequency for each of the indexed fields in
-	// that document. The default field weight is 1.
-	Weights map[string]int
-
-	// Collation defines the collation to use for the index.
-	Collation *Collation
-}
-
-type Collation struct {
-
-	// Locale defines the collation locale.
-	Locale string `bson:"locale"`
-
-	// CaseLevel defines whether to turn case sensitivity on at strength 1 or 2.
-	CaseLevel bool `bson:"caseLevel,omitempty"`
-
-	// CaseFirst may be set to "upper" or "lower" to define whether
-	// to have uppercase or lowercase items first. Default is "off".
-	CaseFirst string `bson:"caseFirst,omitempty"`
-
-	// Strength defines the priority of comparison properties, as follows:
-	//
-	//   1 (primary)    - Strongest level, denote difference between base characters
-	//   2 (secondary)  - Accents in characters are considered secondary differences
-	//   3 (tertiary)   - Upper and lower case differences in characters are
-	//                    distinguished at the tertiary level
-	//   4 (quaternary) - When punctuation is ignored at level 1-3, an additional
-	//                    level can be used to distinguish words with and without
-	//                    punctuation. Should only be used if ignoring punctuation
-	//                    is required or when processing Japanese text.
-	//   5 (identical)  - When all other levels are equal, the identical level is
-	//                    used as a tiebreaker. The Unicode code point values of
-	//                    the NFD form of each string are compared at this level,
-	//                    just in case there is no difference at levels 1-4
-	//
-	// Strength defaults to 3.
-	Strength int `bson:"strength,omitempty"`
-
-	// NumericOrdering defines whether to order numbers based on numerical
-	// order and not collation order.
-	NumericOrdering bool `bson:"numericOrdering,omitempty"`
-
-	// Alternate controls whether spaces and punctuation are considered base characters.
-	// May be set to "non-ignorable" (spaces and punctuation considered base characters)
-	// or "shifted" (spaces and punctuation not considered base characters, and only
-	// distinguished at strength > 3). Defaults to "non-ignorable".
-	Alternate string `bson:"alternate,omitempty"`
-
-	// Backwards defines whether to have secondary differences considered in reverse order,
-	// as done in the French language.
-	Backwards bool `bson:"backwards,omitempty"`
-}
-
-// mgo.v3: Drop Minf and Maxf and transform Min and Max to floats.
-// mgo.v3: Drop DropDups as it's unsupported past 2.8.
-
-type indexKeyInfo struct {
-	name    string
-	key     bson.D
-	weights bson.D
-}
-
-func parseIndexKey(key []string) (*indexKeyInfo, error) {
-	var keyInfo indexKeyInfo
-	isText := false
-	var order interface{}
-	for _, field := range key {
-		raw := field
-		if keyInfo.name != "" {
-			keyInfo.name += "_"
-		}
-		var kind string
-		if field != "" {
-			if field[0] == '$' {
-				if c := strings.Index(field, ":"); c > 1 && c < len(field)-1 {
-					kind = field[1:c]
-					field = field[c+1:]
-					keyInfo.name += field + "_" + kind
-				} else {
-					field = "\x00"
-				}
-			}
-			switch field[0] {
-			case 0:
-				// Logic above failed. Reset and error.
-				field = ""
-			case '@':
-				order = "2d"
-				field = field[1:]
-				// The shell used to render this field as key_ instead of key_2d,
-				// and mgo followed suit. This has been fixed in recent server
-				// releases, and mgo followed as well.
-				keyInfo.name += field + "_2d"
-			case '-':
-				order = -1
-				field = field[1:]
-				keyInfo.name += field + "_-1"
-			case '+':
-				field = field[1:]
-				fallthrough
-			default:
-				if kind == "" {
-					order = 1
-					keyInfo.name += field + "_1"
-				} else {
-					order = kind
-				}
-			}
-		}
-		if field == "" || kind != "" && order != kind {
-			return nil, fmt.Errorf(`invalid index key: want "[$<kind>:][-]<field name>", got %q`, raw)
-		}
-		if kind == "text" {
-			if !isText {
-				keyInfo.key = append(keyInfo.key, bson.DocElem{"_fts", "text"}, bson.DocElem{"_ftsx", 1})
-				isText = true
-			}
-			keyInfo.weights = append(keyInfo.weights, bson.DocElem{field, 1})
-		} else {
-			keyInfo.key = append(keyInfo.key, bson.DocElem{field, order})
-		}
-	}
-	if keyInfo.name == "" {
-		return nil, errors.New("invalid index key: no fields provided")
-	}
-	return &keyInfo, nil
-}
-
-// EnsureIndexKey ensures an index with the given key exists, creating it
-// if necessary.
-//
-// This example:
-//
-//     err := collection.EnsureIndexKey("a", "b")
-//
-// Is equivalent to:
-//
-//     err := collection.EnsureIndex(mgo.Index{Key: []string{"a", "b"}})
-//
-// See the EnsureIndex method for more details.
-func (c *Collection) EnsureIndexKey(key ...string) error {
-	return c.EnsureIndex(Index{Key: key})
-}
-
-// EnsureIndex ensures an index with the given key exists, creating it with
-// the provided parameters if necessary. EnsureIndex does not modify a previously
-// existent index with a matching key. The old index must be dropped first instead.
-//
-// Once EnsureIndex returns successfully, following requests for the same index
-// will not contact the server unless Collection.DropIndex is used to drop the
-// same index, or Session.ResetIndexCache is called.
-//
-// For example:
-//
-//     index := Index{
-//         Key: []string{"lastname", "firstname"},
-//         Unique: true,
-//         DropDups: true,
-//         Background: true, // See notes.
-//         Sparse: true,
-//     }
-//     err := collection.EnsureIndex(index)
-//
-// The Key value determines which fields compose the index. The index ordering
-// will be ascending by default.  To obtain an index with a descending order,
-// the field name should be prefixed by a dash (e.g. []string{"-time"}). It can
-// also be optionally prefixed by an index kind, as in "$text:summary" or
-// "$2d:-point". The key string format is:
-//
-//     [$<kind>:][-]<field name>
-//
-// If the Unique field is true, the index must necessarily contain only a single
-// document per Key.  With DropDups set to true, documents with the same key
-// as a previously indexed one will be dropped rather than an error returned.
-//
-// If Background is true, other connections will be allowed to proceed using
-// the collection without the index while it's being built. Note that the
-// session executing EnsureIndex will be blocked for as long as it takes for
-// the index to be built.
-//
-// If Sparse is true, only documents containing the provided Key fields will be
-// included in the index.  When using a sparse index for sorting, only indexed
-// documents will be returned.
-//
-// If ExpireAfter is non-zero, the server will periodically scan the collection
-// and remove documents containing an indexed time.Time field with a value
-// older than ExpireAfter. See the documentation for details:
-//
-//     http://docs.mongodb.org/manual/tutorial/expire-data
-//
-// Other kinds of indexes are also supported through that API. Here is an example:
-//
-//     index := Index{
-//         Key: []string{"$2d:loc"},
-//         Bits: 26,
-//     }
-//     err := collection.EnsureIndex(index)
-//
-// The example above requests the creation of a "2d" index for the "loc" field.
-//
-// The 2D index bounds may be changed using the Min and Max attributes of the
-// Index value.  The default bound setting of (-180, 180) is suitable for
-// latitude/longitude pairs.
-//
-// The Bits parameter sets the precision of the 2D geohash values.  If not
-// provided, 26 bits are used, which is roughly equivalent to 1 foot of
-// precision for the default (-180, 180) index bounds.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Indexes
-//     http://www.mongodb.org/display/DOCS/Indexing+Advice+and+FAQ
-//     http://www.mongodb.org/display/DOCS/Indexing+as+a+Background+Operation
-//     http://www.mongodb.org/display/DOCS/Geospatial+Indexing
-//     http://www.mongodb.org/display/DOCS/Multikeys
-//
-func (c *Collection) EnsureIndex(index Index) error {
-	keyInfo, err := parseIndexKey(index.Key)
-	if err != nil {
-		return err
-	}
-
-	session := c.Database.Session
-	cacheKey := c.FullName + "\x00" + keyInfo.name
-	if session.cluster().HasCachedIndex(cacheKey) {
-		return nil
-	}
-
-	spec := indexSpec{
-		Name:             keyInfo.name,
-		NS:               c.FullName,
-		Key:              keyInfo.key,
-		Unique:           index.Unique,
-		DropDups:         index.DropDups,
-		Background:       index.Background,
-		Sparse:           index.Sparse,
-		Bits:             index.Bits,
-		Min:              index.Minf,
-		Max:              index.Maxf,
-		BucketSize:       index.BucketSize,
-		ExpireAfter:      int(index.ExpireAfter / time.Second),
-		Weights:          keyInfo.weights,
-		DefaultLanguage:  index.DefaultLanguage,
-		LanguageOverride: index.LanguageOverride,
-		Collation:        index.Collation,
-	}
-
-	if spec.Min == 0 && spec.Max == 0 {
-		spec.Min = float64(index.Min)
-		spec.Max = float64(index.Max)
-	}
-
-	if index.Name != "" {
-		spec.Name = index.Name
-	}
-
-NextField:
-	for name, weight := range index.Weights {
-		for i, elem := range spec.Weights {
-			if elem.Name == name {
-				spec.Weights[i].Value = weight
-				continue NextField
-			}
-		}
-		panic("weight provided for field that is not part of index key: " + name)
-	}
-
-	cloned := session.Clone()
-	defer cloned.Close()
-	cloned.SetMode(Strong, false)
-	cloned.EnsureSafe(&Safe{})
-	db := c.Database.With(cloned)
-
-	// Try with a command first.
-	err = db.Run(bson.D{{"createIndexes", c.Name}, {"indexes", []indexSpec{spec}}}, nil)
-	if isNoCmd(err) {
-		// Command not yet supported. Insert into the indexes collection instead.
-		err = db.C("system.indexes").Insert(&spec)
-	}
-	if err == nil {
-		session.cluster().CacheIndex(cacheKey, true)
-	}
-	return err
-}
-
-// DropIndex drops the index with the provided key from the c collection.
-//
-// See EnsureIndex for details on the accepted key variants.
-//
-// For example:
-//
-//     err1 := collection.DropIndex("firstField", "-secondField")
-//     err2 := collection.DropIndex("customIndexName")
-//
-func (c *Collection) DropIndex(key ...string) error {
-	keyInfo, err := parseIndexKey(key)
-	if err != nil {
-		return err
-	}
-
-	session := c.Database.Session
-	cacheKey := c.FullName + "\x00" + keyInfo.name
-	session.cluster().CacheIndex(cacheKey, false)
-
-	session = session.Clone()
-	defer session.Close()
-	session.SetMode(Strong, false)
-
-	db := c.Database.With(session)
-	result := struct {
-		ErrMsg string
-		Ok     bool
-	}{}
-	err = db.Run(bson.D{{"dropIndexes", c.Name}, {"index", keyInfo.name}}, &result)
-	if err != nil {
-		return err
-	}
-	if !result.Ok {
-		return errors.New(result.ErrMsg)
-	}
-	return nil
-}
-
-// DropIndexName removes the index with the provided index name.
-//
-// For example:
-//
-//     err := collection.DropIndex("customIndexName")
-//
-func (c *Collection) DropIndexName(name string) error {
-	session := c.Database.Session
-
-	session = session.Clone()
-	defer session.Close()
-	session.SetMode(Strong, false)
-
-	c = c.With(session)
-
-	indexes, err := c.Indexes()
-	if err != nil {
-		return err
-	}
-
-	var index Index
-	for _, idx := range indexes {
-		if idx.Name == name {
-			index = idx
-			break
-		}
-	}
-
-	if index.Name != "" {
-		keyInfo, err := parseIndexKey(index.Key)
-		if err != nil {
-			return err
-		}
-
-		cacheKey := c.FullName + "\x00" + keyInfo.name
-		session.cluster().CacheIndex(cacheKey, false)
-	}
-
-	result := struct {
-		ErrMsg string
-		Ok     bool
-	}{}
-	err = c.Database.Run(bson.D{{"dropIndexes", c.Name}, {"index", name}}, &result)
-	if err != nil {
-		return err
-	}
-	if !result.Ok {
-		return errors.New(result.ErrMsg)
-	}
-	return nil
-}
-
-// nonEventual returns a clone of session and ensures it is not Eventual.
-// This guarantees that the server that is used for queries may be reused
-// afterwards when a cursor is received.
-func (session *Session) nonEventual() *Session {
-	cloned := session.Clone()
-	if cloned.consistency == Eventual {
-		cloned.SetMode(Monotonic, false)
-	}
-	return cloned
-}
-
-// Indexes returns a list of all indexes for the collection.
-//
-// For example, this snippet would drop all available indexes:
-//
-//   indexes, err := collection.Indexes()
-//   if err != nil {
-//       return err
-//   }
-//   for _, index := range indexes {
-//       err = collection.DropIndex(index.Key...)
-//       if err != nil {
-//           return err
-//       }
-//   }
-//
-// See the EnsureIndex method for more details on indexes.
-func (c *Collection) Indexes() (indexes []Index, err error) {
-	cloned := c.Database.Session.nonEventual()
-	defer cloned.Close()
-
-	batchSize := int(cloned.queryConfig.op.limit)
-
-	// Try with a command.
-	var result struct {
-		Indexes []bson.Raw
-		Cursor  cursorData
-	}
-	var iter *Iter
-	err = c.Database.With(cloned).Run(bson.D{{"listIndexes", c.Name}, {"cursor", bson.D{{"batchSize", batchSize}}}}, &result)
-	if err == nil {
-		firstBatch := result.Indexes
-		if firstBatch == nil {
-			firstBatch = result.Cursor.FirstBatch
-		}
-		ns := strings.SplitN(result.Cursor.NS, ".", 2)
-		if len(ns) < 2 {
-			iter = c.With(cloned).NewIter(nil, firstBatch, result.Cursor.Id, nil)
-		} else {
-			iter = cloned.DB(ns[0]).C(ns[1]).NewIter(nil, firstBatch, result.Cursor.Id, nil)
-		}
-	} else if isNoCmd(err) {
-		// Command not yet supported. Query the database instead.
-		iter = c.Database.C("system.indexes").Find(bson.M{"ns": c.FullName}).Iter()
-	} else {
-		return nil, err
-	}
-
-	var spec indexSpec
-	for iter.Next(&spec) {
-		indexes = append(indexes, indexFromSpec(spec))
-	}
-	if err = iter.Close(); err != nil {
-		return nil, err
-	}
-	sort.Sort(indexSlice(indexes))
-	return indexes, nil
-}
-
-func indexFromSpec(spec indexSpec) Index {
-	index := Index{
-		Name:             spec.Name,
-		Key:              simpleIndexKey(spec.Key),
-		Unique:           spec.Unique,
-		DropDups:         spec.DropDups,
-		Background:       spec.Background,
-		Sparse:           spec.Sparse,
-		Minf:             spec.Min,
-		Maxf:             spec.Max,
-		Bits:             spec.Bits,
-		BucketSize:       spec.BucketSize,
-		DefaultLanguage:  spec.DefaultLanguage,
-		LanguageOverride: spec.LanguageOverride,
-		ExpireAfter:      time.Duration(spec.ExpireAfter) * time.Second,
-		Collation:        spec.Collation,
-	}
-	if float64(int(spec.Min)) == spec.Min && float64(int(spec.Max)) == spec.Max {
-		index.Min = int(spec.Min)
-		index.Max = int(spec.Max)
-	}
-	if spec.TextIndexVersion > 0 {
-		index.Key = make([]string, len(spec.Weights))
-		index.Weights = make(map[string]int)
-		for i, elem := range spec.Weights {
-			index.Key[i] = "$text:" + elem.Name
-			if w, ok := elem.Value.(int); ok {
-				index.Weights[elem.Name] = w
-			}
-		}
-	}
-	return index
-}
-
-type indexSlice []Index
-
-func (idxs indexSlice) Len() int           { return len(idxs) }
-func (idxs indexSlice) Less(i, j int) bool { return idxs[i].Name < idxs[j].Name }
-func (idxs indexSlice) Swap(i, j int)      { idxs[i], idxs[j] = idxs[j], idxs[i] }
-
-func simpleIndexKey(realKey bson.D) (key []string) {
-	for i := range realKey {
-		field := realKey[i].Name
-		vi, ok := realKey[i].Value.(int)
-		if !ok {
-			vf, _ := realKey[i].Value.(float64)
-			vi = int(vf)
-		}
-		if vi == 1 {
-			key = append(key, field)
-			continue
-		}
-		if vi == -1 {
-			key = append(key, "-"+field)
-			continue
-		}
-		if vs, ok := realKey[i].Value.(string); ok {
-			key = append(key, "$"+vs+":"+field)
-			continue
-		}
-		panic("Got unknown index key type for field " + field)
-	}
-	return
-}
-
-// ResetIndexCache() clears the cache of previously ensured indexes.
-// Following requests to EnsureIndex will contact the server.
-func (s *Session) ResetIndexCache() {
-	s.cluster().ResetIndexCache()
-}
-
-// New creates a new session with the same parameters as the original
-// session, including consistency, batch size, prefetching, safety mode,
-// etc. The returned session will use sockets from the pool, so there's
-// a chance that writes just performed in another session may not yet
-// be visible.
-//
-// Login information from the original session will not be copied over
-// into the new session unless it was provided through the initial URL
-// for the Dial function.
-//
-// See the Copy and Clone methods.
-//
-func (s *Session) New() *Session {
-	s.m.Lock()
-	scopy := copySession(s, false)
-	s.m.Unlock()
-	scopy.Refresh()
-	return scopy
-}
-
-// Copy works just like New, but preserves the exact authentication
-// information from the original session.
-func (s *Session) Copy() *Session {
-	s.m.Lock()
-	scopy := copySession(s, true)
-	s.m.Unlock()
-	scopy.Refresh()
-	return scopy
-}
-
-// Clone works just like Copy, but also reuses the same socket as the original
-// session, in case it had already reserved one due to its consistency
-// guarantees.  This behavior ensures that writes performed in the old session
-// are necessarily observed when using the new session, as long as it was a
-// strong or monotonic session.  That said, it also means that long operations
-// may cause other goroutines using the original session to wait.
-func (s *Session) Clone() *Session {
-	s.m.Lock()
-	scopy := copySession(s, true)
-	s.m.Unlock()
-	return scopy
-}
-
-// Close terminates the session.  It's a runtime error to use a session
-// after it has been closed.
-func (s *Session) Close() {
-	s.m.Lock()
-	if s.cluster_ != nil {
-		debugf("Closing session %p", s)
-		s.unsetSocket()
-		s.cluster_.Release()
-		s.cluster_ = nil
-	}
-	s.m.Unlock()
-}
-
-func (s *Session) cluster() *mongoCluster {
-	if s.cluster_ == nil {
-		panic("Session already closed")
-	}
-	return s.cluster_
-}
-
-// Refresh puts back any reserved sockets in use and restarts the consistency
-// guarantees according to the current consistency setting for the session.
-func (s *Session) Refresh() {
-	s.m.Lock()
-	s.slaveOk = s.consistency != Strong
-	s.unsetSocket()
-	s.m.Unlock()
-}
-
-// SetMode changes the consistency mode for the session.
-//
-// The default mode is Strong.
-//
-// In the Strong consistency mode reads and writes will always be made to
-// the primary server using a unique connection so that reads and writes are
-// fully consistent, ordered, and observing the most up-to-date data.
-// This offers the least benefits in terms of distributing load, but the
-// most guarantees.  See also Monotonic and Eventual.
-//
-// In the Monotonic consistency mode reads may not be entirely up-to-date,
-// but they will always see the history of changes moving forward, the data
-// read will be consistent across sequential queries in the same session,
-// and modifications made within the session will be observed in following
-// queries (read-your-writes).
-//
-// In practice, the Monotonic mode is obtained by performing initial reads
-// on a unique connection to an arbitrary secondary, if one is available,
-// and once the first write happens, the session connection is switched over
-// to the primary server.  This manages to distribute some of the reading
-// load with secondaries, while maintaining some useful guarantees.
-//
-// In the Eventual consistency mode reads will be made to any secondary in the
-// cluster, if one is available, and sequential reads will not necessarily
-// be made with the same connection.  This means that data may be observed
-// out of order.  Writes will of course be issued to the primary, but
-// independent writes in the same Eventual session may also be made with
-// independent connections, so there are also no guarantees in terms of
-// write ordering (no read-your-writes guarantees either).
-//
-// The Eventual mode is the fastest and most resource-friendly, but is
-// also the one offering the least guarantees about ordering of the data
-// read and written.
-//
-// If refresh is true, in addition to ensuring the session is in the given
-// consistency mode, the consistency guarantees will also be reset (e.g.
-// a Monotonic session will be allowed to read from secondaries again).
-// This is equivalent to calling the Refresh function.
-//
-// Shifting between Monotonic and Strong modes will keep a previously
-// reserved connection for the session unless refresh is true or the
-// connection is unsuitable (to a secondary server in a Strong session).
-func (s *Session) SetMode(consistency Mode, refresh bool) {
-	s.m.Lock()
-	debugf("Session %p: setting mode %d with refresh=%v (master=%p, slave=%p)", s, consistency, refresh, s.masterSocket, s.slaveSocket)
-	s.consistency = consistency
-	if refresh {
-		s.slaveOk = s.consistency != Strong
-		s.unsetSocket()
-	} else if s.consistency == Strong {
-		s.slaveOk = false
-	} else if s.masterSocket == nil {
-		s.slaveOk = true
-	}
-	s.m.Unlock()
-}
-
-// Mode returns the current consistency mode for the session.
-func (s *Session) Mode() Mode {
-	s.m.RLock()
-	mode := s.consistency
-	s.m.RUnlock()
-	return mode
-}
-
-// SetSyncTimeout sets the amount of time an operation with this session
-// will wait before returning an error in case a connection to a usable
-// server can't be established. Set it to zero to wait forever. The
-// default value is 7 seconds.
-func (s *Session) SetSyncTimeout(d time.Duration) {
-	s.m.Lock()
-	s.syncTimeout = d
-	s.m.Unlock()
-}
-
-// SetSocketTimeout sets the amount of time to wait for a non-responding
-// socket to the database before it is forcefully closed.
-//
-// The default timeout is 1 minute.
-func (s *Session) SetSocketTimeout(d time.Duration) {
-	s.m.Lock()
-	s.sockTimeout = d
-	if s.masterSocket != nil {
-		s.masterSocket.SetTimeout(d)
-	}
-	if s.slaveSocket != nil {
-		s.slaveSocket.SetTimeout(d)
-	}
-	s.m.Unlock()
-}
-
-// SetCursorTimeout changes the standard timeout period that the server
-// enforces on created cursors. The only supported value right now is
-// 0, which disables the timeout. The standard server timeout is 10 minutes.
-func (s *Session) SetCursorTimeout(d time.Duration) {
-	s.m.Lock()
-	if d == 0 {
-		s.queryConfig.op.flags |= flagNoCursorTimeout
-	} else {
-		panic("SetCursorTimeout: only 0 (disable timeout) supported for now")
-	}
-	s.m.Unlock()
-}
-
-// SetPoolLimit sets the maximum number of sockets in use in a single server
-// before this session will block waiting for a socket to be available.
-// The default limit is 4096.
-//
-// This limit must be set to cover more than any expected workload of the
-// application. It is a bad practice and an unsupported use case to use the
-// database driver to define the concurrency limit of an application. Prevent
-// such concurrency "at the door" instead, by properly restricting the amount
-// of used resources and number of goroutines before they are created.
-func (s *Session) SetPoolLimit(limit int) {
-	s.m.Lock()
-	s.poolLimit = limit
-	s.m.Unlock()
-}
-
-// SetBypassValidation sets whether the server should bypass the registered
-// validation expressions executed when documents are inserted or modified,
-// in the interest of preserving invariants in the collection being modified.
-// The default is to not bypass, and thus to perform the validation
-// expressions registered for modified collections.
-//
-// Document validation was introuced in MongoDB 3.2.
-//
-// Relevant documentation:
-//
-//   https://docs.mongodb.org/manual/release-notes/3.2/#bypass-validation
-//
-func (s *Session) SetBypassValidation(bypass bool) {
-	s.m.Lock()
-	s.bypassValidation = bypass
-	s.m.Unlock()
-}
-
-// SetBatch sets the default batch size used when fetching documents from the
-// database. It's possible to change this setting on a per-query basis as
-// well, using the Query.Batch method.
-//
-// The default batch size is defined by the database itself.  As of this
-// writing, MongoDB will use an initial size of min(100 docs, 4MB) on the
-// first batch, and 4MB on remaining ones.
-func (s *Session) SetBatch(n int) {
-	if n == 1 {
-		// Server interprets 1 as -1 and closes the cursor (!?)
-		n = 2
-	}
-	s.m.Lock()
-	s.queryConfig.op.limit = int32(n)
-	s.m.Unlock()
-}
-
-// SetPrefetch sets the default point at which the next batch of results will be
-// requested.  When there are p*batch_size remaining documents cached in an
-// Iter, the next batch will be requested in background. For instance, when
-// using this:
-//
-//     session.SetBatch(200)
-//     session.SetPrefetch(0.25)
-//
-// and there are only 50 documents cached in the Iter to be processed, the
-// next batch of 200 will be requested. It's possible to change this setting on
-// a per-query basis as well, using the Prefetch method of Query.
-//
-// The default prefetch value is 0.25.
-func (s *Session) SetPrefetch(p float64) {
-	s.m.Lock()
-	s.queryConfig.prefetch = p
-	s.m.Unlock()
-}
-
-// See SetSafe for details on the Safe type.
-type Safe struct {
-	W        int    // Min # of servers to ack before success
-	WMode    string // Write mode for MongoDB 2.0+ (e.g. "majority")
-	WTimeout int    // Milliseconds to wait for W before timing out
-	FSync    bool   // Sync via the journal if present, or via data files sync otherwise
-	J        bool   // Sync via the journal if present
-}
-
-// Safe returns the current safety mode for the session.
-func (s *Session) Safe() (safe *Safe) {
-	s.m.Lock()
-	defer s.m.Unlock()
-	if s.safeOp != nil {
-		cmd := s.safeOp.query.(*getLastError)
-		safe = &Safe{WTimeout: cmd.WTimeout, FSync: cmd.FSync, J: cmd.J}
-		switch w := cmd.W.(type) {
-		case string:
-			safe.WMode = w
-		case int:
-			safe.W = w
-		}
-	}
-	return
-}
-
-// SetSafe changes the session safety mode.
-//
-// If the safe parameter is nil, the session is put in unsafe mode, and writes
-// become fire-and-forget, without error checking.  The unsafe mode is faster
-// since operations won't hold on waiting for a confirmation.
-//
-// If the safe parameter is not nil, any changing query (insert, update, ...)
-// will be followed by a getLastError command with the specified parameters,
-// to ensure the request was correctly processed.
-//
-// The default is &Safe{}, meaning check for errors and use the default
-// behavior for all fields.
-//
-// The safe.W parameter determines how many servers should confirm a write
-// before the operation is considered successful.  If set to 0 or 1, the
-// command will return as soon as the primary is done with the request.
-// If safe.WTimeout is greater than zero, it determines how many milliseconds
-// to wait for the safe.W servers to respond before returning an error.
-//
-// Starting with MongoDB 2.0.0 the safe.WMode parameter can be used instead
-// of W to request for richer semantics. If set to "majority" the server will
-// wait for a majority of members from the replica set to respond before
-// returning. Custom modes may also be defined within the server to create
-// very detailed placement schemas. See the data awareness documentation in
-// the links below for more details (note that MongoDB internally reuses the
-// "w" field name for WMode).
-//
-// If safe.J is true, servers will block until write operations have been
-// committed to the journal. Cannot be used in combination with FSync. Prior
-// to MongoDB 2.6 this option was ignored if the server was running without
-// journaling. Starting with MongoDB 2.6 write operations will fail with an
-// exception if this option is used when the server is running without
-// journaling.
-//
-// If safe.FSync is true and the server is running without journaling, blocks
-// until the server has synced all data files to disk. If the server is running
-// with journaling, this acts the same as the J option, blocking until write
-// operations have been committed to the journal. Cannot be used in
-// combination with J.
-//
-// Since MongoDB 2.0.0, the safe.J option can also be used instead of FSync
-// to force the server to wait for a group commit in case journaling is
-// enabled. The option has no effect if the server has journaling disabled.
-//
-// For example, the following statement will make the session check for
-// errors, without imposing further constraints:
-//
-//     session.SetSafe(&mgo.Safe{})
-//
-// The following statement will force the server to wait for a majority of
-// members of a replica set to return (MongoDB 2.0+ only):
-//
-//     session.SetSafe(&mgo.Safe{WMode: "majority"})
-//
-// The following statement, on the other hand, ensures that at least two
-// servers have flushed the change to disk before confirming the success
-// of operations:
-//
-//     session.EnsureSafe(&mgo.Safe{W: 2, FSync: true})
-//
-// The following statement, on the other hand, disables the verification
-// of errors entirely:
-//
-//     session.SetSafe(nil)
-//
-// See also the EnsureSafe method.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/getLastError+Command
-//     http://www.mongodb.org/display/DOCS/Verifying+Propagation+of+Writes+with+getLastError
-//     http://www.mongodb.org/display/DOCS/Data+Center+Awareness
-//
-func (s *Session) SetSafe(safe *Safe) {
-	s.m.Lock()
-	s.safeOp = nil
-	s.ensureSafe(safe)
-	s.m.Unlock()
-}
-
-// EnsureSafe compares the provided safety parameters with the ones
-// currently in use by the session and picks the most conservative
-// choice for each setting.
-//
-// That is:
-//
-//     - safe.WMode is always used if set.
-//     - safe.W is used if larger than the current W and WMode is empty.
-//     - safe.FSync is always used if true.
-//     - safe.J is used if FSync is false.
-//     - safe.WTimeout is used if set and smaller than the current WTimeout.
-//
-// For example, the following statement will ensure the session is
-// at least checking for errors, without enforcing further constraints.
-// If a more conservative SetSafe or EnsureSafe call was previously done,
-// the following call will be ignored.
-//
-//     session.EnsureSafe(&mgo.Safe{})
-//
-// See also the SetSafe method for details on what each option means.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/getLastError+Command
-//     http://www.mongodb.org/display/DOCS/Verifying+Propagation+of+Writes+with+getLastError
-//     http://www.mongodb.org/display/DOCS/Data+Center+Awareness
-//
-func (s *Session) EnsureSafe(safe *Safe) {
-	s.m.Lock()
-	s.ensureSafe(safe)
-	s.m.Unlock()
-}
-
-func (s *Session) ensureSafe(safe *Safe) {
-	if safe == nil {
-		return
-	}
-
-	var w interface{}
-	if safe.WMode != "" {
-		w = safe.WMode
-	} else if safe.W > 0 {
-		w = safe.W
-	}
-
-	var cmd getLastError
-	if s.safeOp == nil {
-		cmd = getLastError{1, w, safe.WTimeout, safe.FSync, safe.J}
-	} else {
-		// Copy.  We don't want to mutate the existing query.
-		cmd = *(s.safeOp.query.(*getLastError))
-		if cmd.W == nil {
-			cmd.W = w
-		} else if safe.WMode != "" {
-			cmd.W = safe.WMode
-		} else if i, ok := cmd.W.(int); ok && safe.W > i {
-			cmd.W = safe.W
-		}
-		if safe.WTimeout > 0 && safe.WTimeout < cmd.WTimeout {
-			cmd.WTimeout = safe.WTimeout
-		}
-		if safe.FSync {
-			cmd.FSync = true
-			cmd.J = false
-		} else if safe.J && !cmd.FSync {
-			cmd.J = true
-		}
-	}
-	s.safeOp = &queryOp{
-		query:      &cmd,
-		collection: "admin.$cmd",
-		limit:      -1,
-	}
-}
-
-// Run issues the provided command on the "admin" database and
-// and unmarshals its result in the respective argument. The cmd
-// argument may be either a string with the command name itself, in
-// which case an empty document of the form bson.M{cmd: 1} will be used,
-// or it may be a full command document.
-//
-// Note that MongoDB considers the first marshalled key as the command
-// name, so when providing a command with options, it's important to
-// use an ordering-preserving document, such as a struct value or an
-// instance of bson.D.  For instance:
-//
-//     db.Run(bson.D{{"create", "mycollection"}, {"size", 1024}})
-//
-// For commands on arbitrary databases, see the Run method in
-// the Database type.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Commands
-//     http://www.mongodb.org/display/DOCS/List+of+Database+CommandSkips
-//
-func (s *Session) Run(cmd interface{}, result interface{}) error {
-	return s.DB("admin").Run(cmd, result)
-}
-
-// SelectServers restricts communication to servers configured with the
-// given tags. For example, the following statement restricts servers
-// used for reading operations to those with both tag "disk" set to
-// "ssd" and tag "rack" set to 1:
-//
-//     session.SelectServers(bson.D{{"disk", "ssd"}, {"rack", 1}})
-//
-// Multiple sets of tags may be provided, in which case the used server
-// must match all tags within any one set.
-//
-// If a connection was previously assigned to the session due to the
-// current session mode (see Session.SetMode), the tag selection will
-// only be enforced after the session is refreshed.
-//
-// Relevant documentation:
-//
-//     http://docs.mongodb.org/manual/tutorial/configure-replica-set-tag-sets
-//
-func (s *Session) SelectServers(tags ...bson.D) {
-	s.m.Lock()
-	s.queryConfig.op.serverTags = tags
-	s.m.Unlock()
-}
-
-// Ping runs a trivial ping command just to get in touch with the server.
-func (s *Session) Ping() error {
-	return s.Run("ping", nil)
-}
-
-// Fsync flushes in-memory writes to disk on the server the session
-// is established with. If async is true, the call returns immediately,
-// otherwise it returns after the flush has been made.
-func (s *Session) Fsync(async bool) error {
-	return s.Run(bson.D{{"fsync", 1}, {"async", async}}, nil)
-}
-
-// FsyncLock locks all writes in the specific server the session is
-// established with and returns. Any writes attempted to the server
-// after it is successfully locked will block until FsyncUnlock is
-// called for the same server.
-//
-// This method works on secondaries as well, preventing the oplog from
-// being flushed while the server is locked, but since only the server
-// connected to is locked, for locking specific secondaries it may be
-// necessary to establish a connection directly to the secondary (see
-// Dial's connect=direct option).
-//
-// As an important caveat, note that once a write is attempted and
-// blocks, follow up reads will block as well due to the way the
-// lock is internally implemented in the server. More details at:
-//
-//     https://jira.mongodb.org/browse/SERVER-4243
-//
-// FsyncLock is often used for performing consistent backups of
-// the database files on disk.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/fsync+Command
-//     http://www.mongodb.org/display/DOCS/Backups
-//
-func (s *Session) FsyncLock() error {
-	return s.Run(bson.D{{"fsync", 1}, {"lock", true}}, nil)
-}
-
-// FsyncUnlock releases the server for writes. See FsyncLock for details.
-func (s *Session) FsyncUnlock() error {
-	err := s.Run(bson.D{{"fsyncUnlock", 1}}, nil)
-	if isNoCmd(err) {
-		err = s.DB("admin").C("$cmd.sys.unlock").Find(nil).One(nil) // WTF?
-	}
-	return err
-}
-
-// Find prepares a query using the provided document.  The document may be a
-// map or a struct value capable of being marshalled with bson.  The map
-// may be a generic one using interface{} for its key and/or values, such as
-// bson.M, or it may be a properly typed map.  Providing nil as the document
-// is equivalent to providing an empty document such as bson.M{}.
-//
-// Further details of the query may be tweaked using the resulting Query value,
-// and then executed to retrieve results using methods such as One, For,
-// Iter, or Tail.
-//
-// In case the resulting document includes a field named $err or errmsg, which
-// are standard ways for MongoDB to return query errors, the returned err will
-// be set to a *QueryError value including the Err message and the Code.  In
-// those cases, the result argument is still unmarshalled into with the
-// received document so that any other custom values may be obtained if
-// desired.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Querying
-//     http://www.mongodb.org/display/DOCS/Advanced+Queries
-//
-func (c *Collection) Find(query interface{}) *Query {
-	session := c.Database.Session
-	session.m.RLock()
-	q := &Query{session: session, query: session.queryConfig}
-	session.m.RUnlock()
-	q.op.query = query
-	q.op.collection = c.FullName
-	return q
-}
-
-type repairCmd struct {
-	RepairCursor string           `bson:"repairCursor"`
-	Cursor       *repairCmdCursor ",omitempty"
-}
-
-type repairCmdCursor struct {
-	BatchSize int `bson:"batchSize,omitempty"`
-}
-
-// Repair returns an iterator that goes over all recovered documents in the
-// collection, in a best-effort manner. This is most useful when there are
-// damaged data files. Multiple copies of the same document may be returned
-// by the iterator.
-//
-// Repair is supported in MongoDB 2.7.8 and later.
-func (c *Collection) Repair() *Iter {
-	// Clone session and set it to Monotonic mode so that the server
-	// used for the query may be safely obtained afterwards, if
-	// necessary for iteration when a cursor is received.
-	session := c.Database.Session
-	cloned := session.nonEventual()
-	defer cloned.Close()
-
-	batchSize := int(cloned.queryConfig.op.limit)
-
-	var result struct{ Cursor cursorData }
-
-	cmd := repairCmd{
-		RepairCursor: c.Name,
-		Cursor:       &repairCmdCursor{batchSize},
-	}
-
-	clonedc := c.With(cloned)
-	err := clonedc.Database.Run(cmd, &result)
-	return clonedc.NewIter(session, result.Cursor.FirstBatch, result.Cursor.Id, err)
-}
-
-// FindId is a convenience helper equivalent to:
-//
-//     query := collection.Find(bson.M{"_id": id})
-//
-// See the Find method for more details.
-func (c *Collection) FindId(id interface{}) *Query {
-	return c.Find(bson.D{{"_id", id}})
-}
-
-type Pipe struct {
-	session    *Session
-	collection *Collection
-	pipeline   interface{}
-	allowDisk  bool
-	batchSize  int
-}
-
-type pipeCmd struct {
-	Aggregate string
-	Pipeline  interface{}
-	Cursor    *pipeCmdCursor ",omitempty"
-	Explain   bool           ",omitempty"
-	AllowDisk bool           "allowDiskUse,omitempty"
-}
-
-type pipeCmdCursor struct {
-	BatchSize int `bson:"batchSize,omitempty"`
-}
-
-// Pipe prepares a pipeline to aggregate. The pipeline document
-// must be a slice built in terms of the aggregation framework language.
-//
-// For example:
-//
-//     pipe := collection.Pipe([]bson.M{{"$match": bson.M{"name": "Otavio"}}})
-//     iter := pipe.Iter()
-//
-// Relevant documentation:
-//
-//     http://docs.mongodb.org/manual/reference/aggregation
-//     http://docs.mongodb.org/manual/applications/aggregation
-//     http://docs.mongodb.org/manual/tutorial/aggregation-examples
-//
-func (c *Collection) Pipe(pipeline interface{}) *Pipe {
-	session := c.Database.Session
-	session.m.RLock()
-	batchSize := int(session.queryConfig.op.limit)
-	session.m.RUnlock()
-	return &Pipe{
-		session:    session,
-		collection: c,
-		pipeline:   pipeline,
-		batchSize:  batchSize,
-	}
-}
-
-// Iter executes the pipeline and returns an iterator capable of going
-// over all the generated results.
-func (p *Pipe) Iter() *Iter {
-	// Clone session and set it to Monotonic mode so that the server
-	// used for the query may be safely obtained afterwards, if
-	// necessary for iteration when a cursor is received.
-	cloned := p.session.nonEventual()
-	defer cloned.Close()
-	c := p.collection.With(cloned)
-
-	var result struct {
-		Result []bson.Raw // 2.4, no cursors.
-		Cursor cursorData // 2.6+, with cursors.
-	}
-
-	cmd := pipeCmd{
-		Aggregate: c.Name,
-		Pipeline:  p.pipeline,
-		AllowDisk: p.allowDisk,
-		Cursor:    &pipeCmdCursor{p.batchSize},
-	}
-	err := c.Database.Run(cmd, &result)
-	if e, ok := err.(*QueryError); ok && e.Message == `unrecognized field "cursor` {
-		cmd.Cursor = nil
-		cmd.AllowDisk = false
-		err = c.Database.Run(cmd, &result)
-	}
-	firstBatch := result.Result
-	if firstBatch == nil {
-		firstBatch = result.Cursor.FirstBatch
-	}
-	return c.NewIter(p.session, firstBatch, result.Cursor.Id, err)
-}
-
-// NewIter returns a newly created iterator with the provided parameters.
-// Using this method is not recommended unless the desired functionality
-// is not yet exposed via a more convenient interface (Find, Pipe, etc).
-//
-// The optional session parameter associates the lifetime of the returned
-// iterator to an arbitrary session. If nil, the iterator will be bound to
-// c's session.
-//
-// Documents in firstBatch will be individually provided by the returned
-// iterator before documents from cursorId are made available. If cursorId
-// is zero, only the documents in firstBatch are provided.
-//
-// If err is not nil, the iterator's Err method will report it after
-// exhausting documents in firstBatch.
-//
-// NewIter must be called right after the cursor id is obtained, and must not
-// be called on a collection in Eventual mode, because the cursor id is
-// associated with the specific server that returned it. The provided session
-// parameter may be in any mode or state, though.
-//
-func (c *Collection) NewIter(session *Session, firstBatch []bson.Raw, cursorId int64, err error) *Iter {
-	var server *mongoServer
-	csession := c.Database.Session
-	csession.m.RLock()
-	socket := csession.masterSocket
-	if socket == nil {
-		socket = csession.slaveSocket
-	}
-	if socket != nil {
-		server = socket.Server()
-	}
-	csession.m.RUnlock()
-
-	if server == nil {
-		if csession.Mode() == Eventual {
-			panic("Collection.NewIter called in Eventual mode")
-		}
-		if err == nil {
-			err = errors.New("server not available")
-		}
-	}
-
-	if session == nil {
-		session = csession
-	}
-
-	iter := &Iter{
-		session: session,
-		server:  server,
-		timeout: -1,
-		err:     err,
-	}
-	iter.gotReply.L = &iter.m
-	for _, doc := range firstBatch {
-		iter.docData.Push(doc.Data)
-	}
-	if cursorId != 0 {
-		iter.op.cursorId = cursorId
-		iter.op.collection = c.FullName
-		iter.op.replyFunc = iter.replyFunc()
-	}
-	return iter
-}
-
-// All works like Iter.All.
-func (p *Pipe) All(result interface{}) error {
-	return p.Iter().All(result)
-}
-
-// One executes the pipeline and unmarshals the first item from the
-// result set into the result parameter.
-// It returns ErrNotFound if no items are generated by the pipeline.
-func (p *Pipe) One(result interface{}) error {
-	iter := p.Iter()
-	if iter.Next(result) {
-		return nil
-	}
-	if err := iter.Err(); err != nil {
-		return err
-	}
-	return ErrNotFound
-}
-
-// Explain returns a number of details about how the MongoDB server would
-// execute the requested pipeline, such as the number of objects examined,
-// the number of times the read lock was yielded to allow writes to go in,
-// and so on.
-//
-// For example:
-//
-//     var m bson.M
-//     err := collection.Pipe(pipeline).Explain(&m)
-//     if err == nil {
-//         fmt.Printf("Explain: %#v\n", m)
-//     }
-//
-func (p *Pipe) Explain(result interface{}) error {
-	c := p.collection
-	cmd := pipeCmd{
-		Aggregate: c.Name,
-		Pipeline:  p.pipeline,
-		AllowDisk: p.allowDisk,
-		Explain:   true,
-	}
-	return c.Database.Run(cmd, result)
-}
-
-// AllowDiskUse enables writing to the "<dbpath>/_tmp" server directory so
-// that aggregation pipelines do not have to be held entirely in memory.
-func (p *Pipe) AllowDiskUse() *Pipe {
-	p.allowDisk = true
-	return p
-}
-
-// Batch sets the batch size used when fetching documents from the database.
-// It's possible to change this setting on a per-session basis as well, using
-// the Batch method of Session.
-//
-// The default batch size is defined by the database server.
-func (p *Pipe) Batch(n int) *Pipe {
-	p.batchSize = n
-	return p
-}
-
-// mgo.v3: Use a single user-visible error type.
-
-type LastError struct {
-	Err             string
-	Code, N, Waited int
-	FSyncFiles      int `bson:"fsyncFiles"`
-	WTimeout        bool
-	UpdatedExisting bool        `bson:"updatedExisting"`
-	UpsertedId      interface{} `bson:"upserted"`
-
-	modified int
-	ecases   []BulkErrorCase
-}
-
-func (err *LastError) Error() string {
-	return err.Err
-}
-
-type queryError struct {
-	Err           string "$err"
-	ErrMsg        string
-	Assertion     string
-	Code          int
-	AssertionCode int "assertionCode"
-}
-
-type QueryError struct {
-	Code      int
-	Message   string
-	Assertion bool
-}
-
-func (err *QueryError) Error() string {
-	return err.Message
-}
-
-// IsDup returns whether err informs of a duplicate key error because
-// a primary key index or a secondary unique index already has an entry
-// with the given value.
-func IsDup(err error) bool {
-	// Besides being handy, helps with MongoDB bugs SERVER-7164 and SERVER-11493.
-	// What follows makes me sad. Hopefully conventions will be more clear over time.
-	switch e := err.(type) {
-	case *LastError:
-		return e.Code == 11000 || e.Code == 11001 || e.Code == 12582 || e.Code == 16460 && strings.Contains(e.Err, " E11000 ")
-	case *QueryError:
-		return e.Code == 11000 || e.Code == 11001 || e.Code == 12582
-	case *BulkError:
-		for _, ecase := range e.ecases {
-			if !IsDup(ecase.Err) {
-				return false
-			}
-		}
-		return true
-	}
-	return false
-}
-
-// Insert inserts one or more documents in the respective collection.  In
-// case the session is in safe mode (see the SetSafe method) and an error
-// happens while inserting the provided documents, the returned error will
-// be of type *LastError.
-func (c *Collection) Insert(docs ...interface{}) error {
-	_, err := c.writeOp(&insertOp{c.FullName, docs, 0}, true)
-	return err
-}
-
-// Update finds a single document matching the provided selector document
-// and modifies it according to the update document.
-// If the session is in safe mode (see SetSafe) a ErrNotFound error is
-// returned if a document isn't found, or a value of type *LastError
-// when some other error is detected.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Updating
-//     http://www.mongodb.org/display/DOCS/Atomic+Operations
-//
-func (c *Collection) Update(selector interface{}, update interface{}) error {
-	if selector == nil {
-		selector = bson.D{}
-	}
-	op := updateOp{
-		Collection: c.FullName,
-		Selector:   selector,
-		Update:     update,
-	}
-	lerr, err := c.writeOp(&op, true)
-	if err == nil && lerr != nil && !lerr.UpdatedExisting {
-		return ErrNotFound
-	}
-	return err
-}
-
-// UpdateId is a convenience helper equivalent to:
-//
-//     err := collection.Update(bson.M{"_id": id}, update)
-//
-// See the Update method for more details.
-func (c *Collection) UpdateId(id interface{}, update interface{}) error {
-	return c.Update(bson.D{{"_id", id}}, update)
-}
-
-// ChangeInfo holds details about the outcome of an update operation.
-type ChangeInfo struct {
-	// Updated reports the number of existing documents modified.
-	// Due to server limitations, this reports the same value as the Matched field when
-	// talking to MongoDB <= 2.4 and on Upsert and Apply (findAndModify) operations.
-	Updated    int
-	Removed    int         // Number of documents removed
-	Matched    int         // Number of documents matched but not necessarily changed
-	UpsertedId interface{} // Upserted _id field, when not explicitly provided
-}
-
-// UpdateAll finds all documents matching the provided selector document
-// and modifies them according to the update document.
-// If the session is in safe mode (see SetSafe) details of the executed
-// operation are returned in info or an error of type *LastError when
-// some problem is detected. It is not an error for the update to not be
-// applied on any documents because the selector doesn't match.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Updating
-//     http://www.mongodb.org/display/DOCS/Atomic+Operations
-//
-func (c *Collection) UpdateAll(selector interface{}, update interface{}) (info *ChangeInfo, err error) {
-	if selector == nil {
-		selector = bson.D{}
-	}
-	op := updateOp{
-		Collection: c.FullName,
-		Selector:   selector,
-		Update:     update,
-		Flags:      2,
-		Multi:      true,
-	}
-	lerr, err := c.writeOp(&op, true)
-	if err == nil && lerr != nil {
-		info = &ChangeInfo{Updated: lerr.modified, Matched: lerr.N}
-	}
-	return info, err
-}
-
-// Upsert finds a single document matching the provided selector document
-// and modifies it according to the update document.  If no document matching
-// the selector is found, the update document is applied to the selector
-// document and the result is inserted in the collection.
-// If the session is in safe mode (see SetSafe) details of the executed
-// operation are returned in info, or an error of type *LastError when
-// some problem is detected.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Updating
-//     http://www.mongodb.org/display/DOCS/Atomic+Operations
-//
-func (c *Collection) Upsert(selector interface{}, update interface{}) (info *ChangeInfo, err error) {
-	if selector == nil {
-		selector = bson.D{}
-	}
-	op := updateOp{
-		Collection: c.FullName,
-		Selector:   selector,
-		Update:     update,
-		Flags:      1,
-		Upsert:     true,
-	}
-	var lerr *LastError
-	for i := 0; i < maxUpsertRetries; i++ {
-		lerr, err = c.writeOp(&op, true)
-		// Retry duplicate key errors on upserts.
-		// https://docs.mongodb.com/v3.2/reference/method/db.collection.update/#use-unique-indexes
-		if !IsDup(err) {
-			break
-		}
-	}
-	if err == nil && lerr != nil {
-		info = &ChangeInfo{}
-		if lerr.UpdatedExisting {
-			info.Matched = lerr.N
-			info.Updated = lerr.modified
-		} else {
-			info.UpsertedId = lerr.UpsertedId
-		}
-	}
-	return info, err
-}
-
-// UpsertId is a convenience helper equivalent to:
-//
-//     info, err := collection.Upsert(bson.M{"_id": id}, update)
-//
-// See the Upsert method for more details.
-func (c *Collection) UpsertId(id interface{}, update interface{}) (info *ChangeInfo, err error) {
-	return c.Upsert(bson.D{{"_id", id}}, update)
-}
-
-// Remove finds a single document matching the provided selector document
-// and removes it from the database.
-// If the session is in safe mode (see SetSafe) a ErrNotFound error is
-// returned if a document isn't found, or a value of type *LastError
-// when some other error is detected.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Removing
-//
-func (c *Collection) Remove(selector interface{}) error {
-	if selector == nil {
-		selector = bson.D{}
-	}
-	lerr, err := c.writeOp(&deleteOp{c.FullName, selector, 1, 1}, true)
-	if err == nil && lerr != nil && lerr.N == 0 {
-		return ErrNotFound
-	}
-	return err
-}
-
-// RemoveId is a convenience helper equivalent to:
-//
-//     err := collection.Remove(bson.M{"_id": id})
-//
-// See the Remove method for more details.
-func (c *Collection) RemoveId(id interface{}) error {
-	return c.Remove(bson.D{{"_id", id}})
-}
-
-// RemoveAll finds all documents matching the provided selector document
-// and removes them from the database.  In case the session is in safe mode
-// (see the SetSafe method) and an error happens when attempting the change,
-// the returned error will be of type *LastError.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Removing
-//
-func (c *Collection) RemoveAll(selector interface{}) (info *ChangeInfo, err error) {
-	if selector == nil {
-		selector = bson.D{}
-	}
-	lerr, err := c.writeOp(&deleteOp{c.FullName, selector, 0, 0}, true)
-	if err == nil && lerr != nil {
-		info = &ChangeInfo{Removed: lerr.N, Matched: lerr.N}
-	}
-	return info, err
-}
-
-// DropDatabase removes the entire database including all of its collections.
-func (db *Database) DropDatabase() error {
-	return db.Run(bson.D{{"dropDatabase", 1}}, nil)
-}
-
-// DropCollection removes the entire collection including all of its documents.
-func (c *Collection) DropCollection() error {
-	return c.Database.Run(bson.D{{"drop", c.Name}}, nil)
-}
-
-// The CollectionInfo type holds metadata about a collection.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/createCollection+Command
-//     http://www.mongodb.org/display/DOCS/Capped+Collections
-//
-type CollectionInfo struct {
-	// DisableIdIndex prevents the automatic creation of the index
-	// on the _id field for the collection.
-	DisableIdIndex bool
-
-	// ForceIdIndex enforces the automatic creation of the index
-	// on the _id field for the collection. Capped collections,
-	// for example, do not have such an index by default.
-	ForceIdIndex bool
-
-	// If Capped is true new documents will replace old ones when
-	// the collection is full. MaxBytes must necessarily be set
-	// to define the size when the collection wraps around.
-	// MaxDocs optionally defines the number of documents when it
-	// wraps, but MaxBytes still needs to be set.
-	Capped   bool
-	MaxBytes int
-	MaxDocs  int
-
-	// Validator contains a validation expression that defines which
-	// documents should be considered valid for this collection.
-	Validator interface{}
-
-	// ValidationLevel may be set to "strict" (the default) to force
-	// MongoDB to validate all documents on inserts and updates, to
-	// "moderate" to apply the validation rules only to documents
-	// that already fulfill the validation criteria, or to "off" for
-	// disabling validation entirely.
-	ValidationLevel string
-
-	// ValidationAction determines how MongoDB handles documents that
-	// violate the validation rules. It may be set to "error" (the default)
-	// to reject inserts or updates that violate the rules, or to "warn"
-	// to log invalid operations but allow them to proceed.
-	ValidationAction string
-
-	// StorageEngine allows specifying collection options for the
-	// storage engine in use. The map keys must hold the storage engine
-	// name for which options are being specified.
-	StorageEngine interface{}
-}
-
-// Create explicitly creates the c collection with details of info.
-// MongoDB creates collections automatically on use, so this method
-// is only necessary when creating collection with non-default
-// characteristics, such as capped collections.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/createCollection+Command
-//     http://www.mongodb.org/display/DOCS/Capped+Collections
-//
-func (c *Collection) Create(info *CollectionInfo) error {
-	cmd := make(bson.D, 0, 4)
-	cmd = append(cmd, bson.DocElem{"create", c.Name})
-	if info.Capped {
-		if info.MaxBytes < 1 {
-			return fmt.Errorf("Collection.Create: with Capped, MaxBytes must also be set")
-		}
-		cmd = append(cmd, bson.DocElem{"capped", true})
-		cmd = append(cmd, bson.DocElem{"size", info.MaxBytes})
-		if info.MaxDocs > 0 {
-			cmd = append(cmd, bson.DocElem{"max", info.MaxDocs})
-		}
-	}
-	if info.DisableIdIndex {
-		cmd = append(cmd, bson.DocElem{"autoIndexId", false})
-	}
-	if info.ForceIdIndex {
-		cmd = append(cmd, bson.DocElem{"autoIndexId", true})
-	}
-	if info.Validator != nil {
-		cmd = append(cmd, bson.DocElem{"validator", info.Validator})
-	}
-	if info.ValidationLevel != "" {
-		cmd = append(cmd, bson.DocElem{"validationLevel", info.ValidationLevel})
-	}
-	if info.ValidationAction != "" {
-		cmd = append(cmd, bson.DocElem{"validationAction", info.ValidationAction})
-	}
-	if info.StorageEngine != nil {
-		cmd = append(cmd, bson.DocElem{"storageEngine", info.StorageEngine})
-	}
-	return c.Database.Run(cmd, nil)
-}
-
-// Batch sets the batch size used when fetching documents from the database.
-// It's possible to change this setting on a per-session basis as well, using
-// the Batch method of Session.
-
-// The default batch size is defined by the database itself.  As of this
-// writing, MongoDB will use an initial size of min(100 docs, 4MB) on the
-// first batch, and 4MB on remaining ones.
-func (q *Query) Batch(n int) *Query {
-	if n == 1 {
-		// Server interprets 1 as -1 and closes the cursor (!?)
-		n = 2
-	}
-	q.m.Lock()
-	q.op.limit = int32(n)
-	q.m.Unlock()
-	return q
-}
-
-// Prefetch sets the point at which the next batch of results will be requested.
-// When there are p*batch_size remaining documents cached in an Iter, the next
-// batch will be requested in background. For instance, when using this:
-//
-//     query.Batch(200).Prefetch(0.25)
-//
-// and there are only 50 documents cached in the Iter to be processed, the
-// next batch of 200 will be requested. It's possible to change this setting on
-// a per-session basis as well, using the SetPrefetch method of Session.
-//
-// The default prefetch value is 0.25.
-func (q *Query) Prefetch(p float64) *Query {
-	q.m.Lock()
-	q.prefetch = p
-	q.m.Unlock()
-	return q
-}
-
-// Skip skips over the n initial documents from the query results.  Note that
-// this only makes sense with capped collections where documents are naturally
-// ordered by insertion time, or with sorted results.
-func (q *Query) Skip(n int) *Query {
-	q.m.Lock()
-	q.op.skip = int32(n)
-	q.m.Unlock()
-	return q
-}
-
-// Limit restricts the maximum number of documents retrieved to n, and also
-// changes the batch size to the same value.  Once n documents have been
-// returned by Next, the following call will return ErrNotFound.
-func (q *Query) Limit(n int) *Query {
-	q.m.Lock()
-	switch {
-	case n == 1:
-		q.limit = 1
-		q.op.limit = -1
-	case n == math.MinInt32: // -MinInt32 == -MinInt32
-		q.limit = math.MaxInt32
-		q.op.limit = math.MinInt32 + 1
-	case n < 0:
-		q.limit = int32(-n)
-		q.op.limit = int32(n)
-	default:
-		q.limit = int32(n)
-		q.op.limit = int32(n)
-	}
-	q.m.Unlock()
-	return q
-}
-
-// Select enables selecting which fields should be retrieved for the results
-// found. For example, the following query would only retrieve the name field:
-//
-//     err := collection.Find(nil).Select(bson.M{"name": 1}).One(&result)
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Retrieving+a+Subset+of+Fields
-//
-func (q *Query) Select(selector interface{}) *Query {
-	q.m.Lock()
-	q.op.selector = selector
-	q.m.Unlock()
-	return q
-}
-
-// Sort asks the database to order returned documents according to the
-// provided field names. A field name may be prefixed by - (minus) for
-// it to be sorted in reverse order.
-//
-// For example:
-//
-//     query1 := collection.Find(nil).Sort("firstname", "lastname")
-//     query2 := collection.Find(nil).Sort("-age")
-//     query3 := collection.Find(nil).Sort("$natural")
-//     query4 := collection.Find(nil).Select(bson.M{"score": bson.M{"$meta": "textScore"}}).Sort("$textScore:score")
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Sorting+and+Natural+Order
-//
-func (q *Query) Sort(fields ...string) *Query {
-	q.m.Lock()
-	var order bson.D
-	for _, field := range fields {
-		n := 1
-		var kind string
-		if field != "" {
-			if field[0] == '$' {
-				if c := strings.Index(field, ":"); c > 1 && c < len(field)-1 {
-					kind = field[1:c]
-					field = field[c+1:]
-				}
-			}
-			switch field[0] {
-			case '+':
-				field = field[1:]
-			case '-':
-				n = -1
-				field = field[1:]
-			}
-		}
-		if field == "" {
-			panic("Sort: empty field name")
-		}
-		if kind == "textScore" {
-			order = append(order, bson.DocElem{field, bson.M{"$meta": kind}})
-		} else {
-			order = append(order, bson.DocElem{field, n})
-		}
-	}
-	q.op.options.OrderBy = order
-	q.op.hasOptions = true
-	q.m.Unlock()
-	return q
-}
-
-// Explain returns a number of details about how the MongoDB server would
-// execute the requested query, such as the number of objects examined,
-// the number of times the read lock was yielded to allow writes to go in,
-// and so on.
-//
-// For example:
-//
-//     m := bson.M{}
-//     err := collection.Find(bson.M{"filename": name}).Explain(m)
-//     if err == nil {
-//         fmt.Printf("Explain: %#v\n", m)
-//     }
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Optimization
-//     http://www.mongodb.org/display/DOCS/Query+Optimizer
-//
-func (q *Query) Explain(result interface{}) error {
-	q.m.Lock()
-	clone := &Query{session: q.session, query: q.query}
-	q.m.Unlock()
-	clone.op.options.Explain = true
-	clone.op.hasOptions = true
-	if clone.op.limit > 0 {
-		clone.op.limit = -q.op.limit
-	}
-	iter := clone.Iter()
-	if iter.Next(result) {
-		return nil
-	}
-	return iter.Close()
-}
-
-// TODO: Add Collection.Explain. See https://goo.gl/1MDlvz.
-
-// Hint will include an explicit "hint" in the query to force the server
-// to use a specified index, potentially improving performance in some
-// situations.  The provided parameters are the fields that compose the
-// key of the index to be used.  For details on how the indexKey may be
-// built, see the EnsureIndex method.
-//
-// For example:
-//
-//     query := collection.Find(bson.M{"firstname": "Joe", "lastname": "Winter"})
-//     query.Hint("lastname", "firstname")
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Optimization
-//     http://www.mongodb.org/display/DOCS/Query+Optimizer
-//
-func (q *Query) Hint(indexKey ...string) *Query {
-	q.m.Lock()
-	keyInfo, err := parseIndexKey(indexKey)
-	q.op.options.Hint = keyInfo.key
-	q.op.hasOptions = true
-	q.m.Unlock()
-	if err != nil {
-		panic(err)
-	}
-	return q
-}
-
-// SetMaxScan constrains the query to stop after scanning the specified
-// number of documents.
-//
-// This modifier is generally used to prevent potentially long running
-// queries from disrupting performance by scanning through too much data.
-func (q *Query) SetMaxScan(n int) *Query {
-	q.m.Lock()
-	q.op.options.MaxScan = n
-	q.op.hasOptions = true
-	q.m.Unlock()
-	return q
-}
-
-// SetMaxTime constrains the query to stop after running for the specified time.
-//
-// When the time limit is reached MongoDB automatically cancels the query.
-// This can be used to efficiently prevent and identify unexpectedly slow queries.
-//
-// A few important notes about the mechanism enforcing this limit:
-//
-//  - Requests can block behind locking operations on the server, and that blocking
-//    time is not accounted for. In other words, the timer starts ticking only after
-//    the actual start of the query when it initially acquires the appropriate lock;
-//
-//  - Operations are interrupted only at interrupt points where an operation can be
-//    safely aborted – the total execution time may exceed the specified value;
-//
-//  - The limit can be applied to both CRUD operations and commands, but not all
-//    commands are interruptible;
-//
-//  - While iterating over results, computing follow up batches is included in the
-//    total time and the iteration continues until the alloted time is over, but
-//    network roundtrips are not taken into account for the limit.
-//
-//  - This limit does not override the inactive cursor timeout for idle cursors
-//    (default is 10 min).
-//
-// This mechanism was introduced in MongoDB 2.6.
-//
-// Relevant documentation:
-//
-//   http://blog.mongodb.org/post/83621787773/maxtimems-and-query-optimizer-introspection-in
-//
-func (q *Query) SetMaxTime(d time.Duration) *Query {
-	q.m.Lock()
-	q.op.options.MaxTimeMS = int(d / time.Millisecond)
-	q.op.hasOptions = true
-	q.m.Unlock()
-	return q
-}
-
-// Snapshot will force the performed query to make use of an available
-// index on the _id field to prevent the same document from being returned
-// more than once in a single iteration. This might happen without this
-// setting in situations when the document changes in size and thus has to
-// be moved while the iteration is running.
-//
-// Because snapshot mode traverses the _id index, it may not be used with
-// sorting or explicit hints. It also cannot use any other index for the
-// query.
-//
-// Even with snapshot mode, items inserted or deleted during the query may
-// or may not be returned; that is, this mode is not a true point-in-time
-// snapshot.
-//
-// The same effect of Snapshot may be obtained by using any unique index on
-// field(s) that will not be modified (best to use Hint explicitly too).
-// A non-unique index (such as creation time) may be made unique by
-// appending _id to the index when creating it.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/How+to+do+Snapshotted+Queries+in+the+Mongo+Database
-//
-func (q *Query) Snapshot() *Query {
-	q.m.Lock()
-	q.op.options.Snapshot = true
-	q.op.hasOptions = true
-	q.m.Unlock()
-	return q
-}
-
-// Comment adds a comment to the query to identify it in the database profiler output.
-//
-// Relevant documentation:
-//
-//     http://docs.mongodb.org/manual/reference/operator/meta/comment
-//     http://docs.mongodb.org/manual/reference/command/profile
-//     http://docs.mongodb.org/manual/administration/analyzing-mongodb-performance/#database-profiling
-//
-func (q *Query) Comment(comment string) *Query {
-	q.m.Lock()
-	q.op.options.Comment = comment
-	q.op.hasOptions = true
-	q.m.Unlock()
-	return q
-}
-
-// LogReplay enables an option that optimizes queries that are typically
-// made on the MongoDB oplog for replaying it. This is an internal
-// implementation aspect and most likely uninteresting for other uses.
-// It has seen at least one use case, though, so it's exposed via the API.
-func (q *Query) LogReplay() *Query {
-	q.m.Lock()
-	q.op.flags |= flagLogReplay
-	q.m.Unlock()
-	return q
-}
-
-func checkQueryError(fullname string, d []byte) error {
-	l := len(d)
-	if l < 16 {
-		return nil
-	}
-	if d[5] == '$' && d[6] == 'e' && d[7] == 'r' && d[8] == 'r' && d[9] == '\x00' && d[4] == '\x02' {
-		goto Error
-	}
-	if len(fullname) < 5 || fullname[len(fullname)-5:] != ".$cmd" {
-		return nil
-	}
-	for i := 0; i+8 < l; i++ {
-		if d[i] == '\x02' && d[i+1] == 'e' && d[i+2] == 'r' && d[i+3] == 'r' && d[i+4] == 'm' && d[i+5] == 's' && d[i+6] == 'g' && d[i+7] == '\x00' {
-			goto Error
-		}
-	}
-	return nil
-
-Error:
-	result := &queryError{}
-	bson.Unmarshal(d, result)
-	if result.Err == "" && result.ErrMsg == "" {
-		return nil
-	}
-	if result.AssertionCode != 0 && result.Assertion != "" {
-		return &QueryError{Code: result.AssertionCode, Message: result.Assertion, Assertion: true}
-	}
-	if result.Err != "" {
-		return &QueryError{Code: result.Code, Message: result.Err}
-	}
-	return &QueryError{Code: result.Code, Message: result.ErrMsg}
-}
-
-// One executes the query and unmarshals the first obtained document into the
-// result argument.  The result must be a struct or map value capable of being
-// unmarshalled into by gobson.  This function blocks until either a result
-// is available or an error happens.  For example:
-//
-//     err := collection.Find(bson.M{"a": 1}).One(&result)
-//
-// In case the resulting document includes a field named $err or errmsg, which
-// are standard ways for MongoDB to return query errors, the returned err will
-// be set to a *QueryError value including the Err message and the Code.  In
-// those cases, the result argument is still unmarshalled into with the
-// received document so that any other custom values may be obtained if
-// desired.
-//
-func (q *Query) One(result interface{}) (err error) {
-	q.m.Lock()
-	session := q.session
-	op := q.op // Copy.
-	q.m.Unlock()
-
-	socket, err := session.acquireSocket(true)
-	if err != nil {
-		return err
-	}
-	defer socket.Release()
-
-	op.limit = -1
-
-	session.prepareQuery(&op)
-
-	expectFindReply := prepareFindOp(socket, &op, 1)
-
-	data, err := socket.SimpleQuery(&op)
-	if err != nil {
-		return err
-	}
-	if data == nil {
-		return ErrNotFound
-	}
-	if expectFindReply {
-		var findReply struct {
-			Ok     bool
-			Code   int
-			Errmsg string
-			Cursor cursorData
-		}
-		err = bson.Unmarshal(data, &findReply)
-		if err != nil {
-			return err
-		}
-		if !findReply.Ok && findReply.Errmsg != "" {
-			return &QueryError{Code: findReply.Code, Message: findReply.Errmsg}
-		}
-		if len(findReply.Cursor.FirstBatch) == 0 {
-			return ErrNotFound
-		}
-		data = findReply.Cursor.FirstBatch[0].Data
-	}
-	if result != nil {
-		err = bson.Unmarshal(data, result)
-		if err == nil {
-			debugf("Query %p document unmarshaled: %#v", q, result)
-		} else {
-			debugf("Query %p document unmarshaling failed: %#v", q, err)
-			return err
-		}
-	}
-	return checkQueryError(op.collection, data)
-}
-
-// prepareFindOp translates op from being an old-style wire protocol query into
-// a new-style find command if that's supported by the MongoDB server (3.2+).
-// It returns whether to expect a find command result or not. Note op may be
-// translated into an explain command, in which case the function returns false.
-func prepareFindOp(socket *mongoSocket, op *queryOp, limit int32) bool {
-	if socket.ServerInfo().MaxWireVersion < 4 || op.collection == "admin.$cmd" {
-		return false
-	}
-
-	nameDot := strings.Index(op.collection, ".")
-	if nameDot < 0 {
-		panic("invalid query collection name: " + op.collection)
-	}
-
-	find := findCmd{
-		Collection:  op.collection[nameDot+1:],
-		Filter:      op.query,
-		Projection:  op.selector,
-		Sort:        op.options.OrderBy,
-		Skip:        op.skip,
-		Limit:       limit,
-		MaxTimeMS:   op.options.MaxTimeMS,
-		MaxScan:     op.options.MaxScan,
-		Hint:        op.options.Hint,
-		Comment:     op.options.Comment,
-		Snapshot:    op.options.Snapshot,
-		OplogReplay: op.flags&flagLogReplay != 0,
-	}
-	if op.limit < 0 {
-		find.BatchSize = -op.limit
-		find.SingleBatch = true
-	} else {
-		find.BatchSize = op.limit
-	}
-
-	explain := op.options.Explain
-
-	op.collection = op.collection[:nameDot] + ".$cmd"
-	op.query = &find
-	op.skip = 0
-	op.limit = -1
-	op.options = queryWrapper{}
-	op.hasOptions = false
-
-	if explain {
-		op.query = bson.D{{"explain", op.query}}
-		return false
-	}
-	return true
-}
-
-type cursorData struct {
-	FirstBatch []bson.Raw "firstBatch"
-	NextBatch  []bson.Raw "nextBatch"
-	NS         string
-	Id         int64
-}
-
-// findCmd holds the command used for performing queries on MongoDB 3.2+.
-//
-// Relevant documentation:
-//
-//     https://docs.mongodb.org/master/reference/command/find/#dbcmd.find
-//
-type findCmd struct {
-	Collection          string      `bson:"find"`
-	Filter              interface{} `bson:"filter,omitempty"`
-	Sort                interface{} `bson:"sort,omitempty"`
-	Projection          interface{} `bson:"projection,omitempty"`
-	Hint                interface{} `bson:"hint,omitempty"`
-	Skip                interface{} `bson:"skip,omitempty"`
-	Limit               int32       `bson:"limit,omitempty"`
-	BatchSize           int32       `bson:"batchSize,omitempty"`
-	SingleBatch         bool        `bson:"singleBatch,omitempty"`
-	Comment             string      `bson:"comment,omitempty"`
-	MaxScan             int         `bson:"maxScan,omitempty"`
-	MaxTimeMS           int         `bson:"maxTimeMS,omitempty"`
-	ReadConcern         interface{} `bson:"readConcern,omitempty"`
-	Max                 interface{} `bson:"max,omitempty"`
-	Min                 interface{} `bson:"min,omitempty"`
-	ReturnKey           bool        `bson:"returnKey,omitempty"`
-	ShowRecordId        bool        `bson:"showRecordId,omitempty"`
-	Snapshot            bool        `bson:"snapshot,omitempty"`
-	Tailable            bool        `bson:"tailable,omitempty"`
-	AwaitData           bool        `bson:"awaitData,omitempty"`
-	OplogReplay         bool        `bson:"oplogReplay,omitempty"`
-	NoCursorTimeout     bool        `bson:"noCursorTimeout,omitempty"`
-	AllowPartialResults bool        `bson:"allowPartialResults,omitempty"`
-}
-
-// getMoreCmd holds the command used for requesting more query results on MongoDB 3.2+.
-//
-// Relevant documentation:
-//
-//     https://docs.mongodb.org/master/reference/command/getMore/#dbcmd.getMore
-//
-type getMoreCmd struct {
-	CursorId   int64  `bson:"getMore"`
-	Collection string `bson:"collection"`
-	BatchSize  int32  `bson:"batchSize,omitempty"`
-	MaxTimeMS  int64  `bson:"maxTimeMS,omitempty"`
-}
-
-// run duplicates the behavior of collection.Find(query).One(&result)
-// as performed by Database.Run, specializing the logic for running
-// database commands on a given socket.
-func (db *Database) run(socket *mongoSocket, cmd, result interface{}) (err error) {
-	// Database.Run:
-	if name, ok := cmd.(string); ok {
-		cmd = bson.D{{name, 1}}
-	}
-
-	// Collection.Find:
-	session := db.Session
-	session.m.RLock()
-	op := session.queryConfig.op // Copy.
-	session.m.RUnlock()
-	op.query = cmd
-	op.collection = db.Name + ".$cmd"
-
-	// Query.One:
-	session.prepareQuery(&op)
-	op.limit = -1
-
-	data, err := socket.SimpleQuery(&op)
-	if err != nil {
-		return err
-	}
-	if data == nil {
-		return ErrNotFound
-	}
-	if result != nil {
-		err = bson.Unmarshal(data, result)
-		if err != nil {
-			debugf("Run command unmarshaling failed: %#v", op, err)
-			return err
-		}
-		if globalDebug && globalLogger != nil {
-			var res bson.M
-			bson.Unmarshal(data, &res)
-			debugf("Run command unmarshaled: %#v, result: %#v", op, res)
-		}
-	}
-	return checkQueryError(op.collection, data)
-}
-
-// The DBRef type implements support for the database reference MongoDB
-// convention as supported by multiple drivers.  This convention enables
-// cross-referencing documents between collections and databases using
-// a structure which includes a collection name, a document id, and
-// optionally a database name.
-//
-// See the FindRef methods on Session and on Database.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Database+References
-//
-type DBRef struct {
-	Collection string      `bson:"$ref"`
-	Id         interface{} `bson:"$id"`
-	Database   string      `bson:"$db,omitempty"`
-}
-
-// NOTE: Order of fields for DBRef above does matter, per documentation.
-
-// FindRef returns a query that looks for the document in the provided
-// reference. If the reference includes the DB field, the document will
-// be retrieved from the respective database.
-//
-// See also the DBRef type and the FindRef method on Session.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Database+References
-//
-func (db *Database) FindRef(ref *DBRef) *Query {
-	var c *Collection
-	if ref.Database == "" {
-		c = db.C(ref.Collection)
-	} else {
-		c = db.Session.DB(ref.Database).C(ref.Collection)
-	}
-	return c.FindId(ref.Id)
-}
-
-// FindRef returns a query that looks for the document in the provided
-// reference. For a DBRef to be resolved correctly at the session level
-// it must necessarily have the optional DB field defined.
-//
-// See also the DBRef type and the FindRef method on Database.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Database+References
-//
-func (s *Session) FindRef(ref *DBRef) *Query {
-	if ref.Database == "" {
-		panic(errors.New(fmt.Sprintf("Can't resolve database for %#v", ref)))
-	}
-	c := s.DB(ref.Database).C(ref.Collection)
-	return c.FindId(ref.Id)
-}
-
-// CollectionNames returns the collection names present in the db database.
-func (db *Database) CollectionNames() (names []string, err error) {
-	// Clone session and set it to Monotonic mode so that the server
-	// used for the query may be safely obtained afterwards, if
-	// necessary for iteration when a cursor is received.
-	cloned := db.Session.nonEventual()
-	defer cloned.Close()
-
-	batchSize := int(cloned.queryConfig.op.limit)
-
-	// Try with a command.
-	var result struct {
-		Collections []bson.Raw
-		Cursor      cursorData
-	}
-	err = db.With(cloned).Run(bson.D{{"listCollections", 1}, {"cursor", bson.D{{"batchSize", batchSize}}}}, &result)
-	if err == nil {
-		firstBatch := result.Collections
-		if firstBatch == nil {
-			firstBatch = result.Cursor.FirstBatch
-		}
-		var iter *Iter
-		ns := strings.SplitN(result.Cursor.NS, ".", 2)
-		if len(ns) < 2 {
-			iter = db.With(cloned).C("").NewIter(nil, firstBatch, result.Cursor.Id, nil)
-		} else {
-			iter = cloned.DB(ns[0]).C(ns[1]).NewIter(nil, firstBatch, result.Cursor.Id, nil)
-		}
-		var coll struct{ Name string }
-		for iter.Next(&coll) {
-			names = append(names, coll.Name)
-		}
-		if err := iter.Close(); err != nil {
-			return nil, err
-		}
-		sort.Strings(names)
-		return names, err
-	}
-	if err != nil && !isNoCmd(err) {
-		return nil, err
-	}
-
-	// Command not yet supported. Query the database instead.
-	nameIndex := len(db.Name) + 1
-	iter := db.C("system.namespaces").Find(nil).Iter()
-	var coll struct{ Name string }
-	for iter.Next(&coll) {
-		if strings.Index(coll.Name, "$") < 0 || strings.Index(coll.Name, ".oplog.$") >= 0 {
-			names = append(names, coll.Name[nameIndex:])
-		}
-	}
-	if err := iter.Close(); err != nil {
-		return nil, err
-	}
-	sort.Strings(names)
-	return names, nil
-}
-
-type dbNames struct {
-	Databases []struct {
-		Name  string
-		Empty bool
-	}
-}
-
-// DatabaseNames returns the names of non-empty databases present in the cluster.
-func (s *Session) DatabaseNames() (names []string, err error) {
-	var result dbNames
-	err = s.Run("listDatabases", &result)
-	if err != nil {
-		return nil, err
-	}
-	for _, db := range result.Databases {
-		if !db.Empty {
-			names = append(names, db.Name)
-		}
-	}
-	sort.Strings(names)
-	return names, nil
-}
-
-// Iter executes the query and returns an iterator capable of going over all
-// the results. Results will be returned in batches of configurable
-// size (see the Batch method) and more documents will be requested when a
-// configurable number of documents is iterated over (see the Prefetch method).
-func (q *Query) Iter() *Iter {
-	q.m.Lock()
-	session := q.session
-	op := q.op
-	prefetch := q.prefetch
-	limit := q.limit
-	q.m.Unlock()
-
-	iter := &Iter{
-		session:  session,
-		prefetch: prefetch,
-		limit:    limit,
-		timeout:  -1,
-	}
-	iter.gotReply.L = &iter.m
-	iter.op.collection = op.collection
-	iter.op.limit = op.limit
-	iter.op.replyFunc = iter.replyFunc()
-	iter.docsToReceive++
-
-	socket, err := session.acquireSocket(true)
-	if err != nil {
-		iter.err = err
-		return iter
-	}
-	defer socket.Release()
-
-	session.prepareQuery(&op)
-	op.replyFunc = iter.op.replyFunc
-
-	if prepareFindOp(socket, &op, limit) {
-		iter.findCmd = true
-	}
-
-	iter.server = socket.Server()
-	err = socket.Query(&op)
-	if err != nil {
-		// Must lock as the query is already out and it may call replyFunc.
-		iter.m.Lock()
-		iter.err = err
-		iter.m.Unlock()
-	}
-
-	return iter
-}
-
-// Tail returns a tailable iterator. Unlike a normal iterator, a
-// tailable iterator may wait for new values to be inserted in the
-// collection once the end of the current result set is reached,
-// A tailable iterator may only be used with capped collections.
-//
-// The timeout parameter indicates how long Next will block waiting
-// for a result before timing out.  If set to -1, Next will not
-// timeout, and will continue waiting for a result for as long as
-// the cursor is valid and the session is not closed. If set to 0,
-// Next times out as soon as it reaches the end of the result set.
-// Otherwise, Next will wait for at least the given number of
-// seconds for a new document to be available before timing out.
-//
-// On timeouts, Next will unblock and return false, and the Timeout
-// method will return true if called. In these cases, Next may still
-// be called again on the same iterator to check if a new value is
-// available at the current cursor position, and again it will block
-// according to the specified timeoutSecs. If the cursor becomes
-// invalid, though, both Next and Timeout will return false and
-// the query must be restarted.
-//
-// The following example demonstrates timeout handling and query
-// restarting:
-//
-//    iter := collection.Find(nil).Sort("$natural").Tail(5 * time.Second)
-//    for {
-//         for iter.Next(&result) {
-//             fmt.Println(result.Id)
-//             lastId = result.Id
-//         }
-//         if iter.Err() != nil {
-//             return iter.Close()
-//         }
-//         if iter.Timeout() {
-//             continue
-//         }
-//         query := collection.Find(bson.M{"_id": bson.M{"$gt": lastId}})
-//         iter = query.Sort("$natural").Tail(5 * time.Second)
-//    }
-//    iter.Close()
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Tailable+Cursors
-//     http://www.mongodb.org/display/DOCS/Capped+Collections
-//     http://www.mongodb.org/display/DOCS/Sorting+and+Natural+Order
-//
-func (q *Query) Tail(timeout time.Duration) *Iter {
-	q.m.Lock()
-	session := q.session
-	op := q.op
-	prefetch := q.prefetch
-	q.m.Unlock()
-
-	iter := &Iter{session: session, prefetch: prefetch}
-	iter.gotReply.L = &iter.m
-	iter.timeout = timeout
-	iter.op.collection = op.collection
-	iter.op.limit = op.limit
-	iter.op.replyFunc = iter.replyFunc()
-	iter.docsToReceive++
-	session.prepareQuery(&op)
-	op.replyFunc = iter.op.replyFunc
-	op.flags |= flagTailable | flagAwaitData
-
-	socket, err := session.acquireSocket(true)
-	if err != nil {
-		iter.err = err
-	} else {
-		iter.server = socket.Server()
-		err = socket.Query(&op)
-		if err != nil {
-			// Must lock as the query is already out and it may call replyFunc.
-			iter.m.Lock()
-			iter.err = err
-			iter.m.Unlock()
-		}
-		socket.Release()
-	}
-	return iter
-}
-
-func (s *Session) prepareQuery(op *queryOp) {
-	s.m.RLock()
-	op.mode = s.consistency
-	if s.slaveOk {
-		op.flags |= flagSlaveOk
-	}
-	s.m.RUnlock()
-	return
-}
-
-// Err returns nil if no errors happened during iteration, or the actual
-// error otherwise.
-//
-// In case a resulting document included a field named $err or errmsg, which are
-// standard ways for MongoDB to report an improper query, the returned value has
-// a *QueryError type, and includes the Err message and the Code.
-func (iter *Iter) Err() error {
-	iter.m.Lock()
-	err := iter.err
-	iter.m.Unlock()
-	if err == ErrNotFound {
-		return nil
-	}
-	return err
-}
-
-// Close kills the server cursor used by the iterator, if any, and returns
-// nil if no errors happened during iteration, or the actual error otherwise.
-//
-// Server cursors are automatically closed at the end of an iteration, which
-// means close will do nothing unless the iteration was interrupted before
-// the server finished sending results to the driver. If Close is not called
-// in such a situation, the cursor will remain available at the server until
-// the default cursor timeout period is reached. No further problems arise.
-//
-// Close is idempotent. That means it can be called repeatedly and will
-// return the same result every time.
-//
-// In case a resulting document included a field named $err or errmsg, which are
-// standard ways for MongoDB to report an improper query, the returned value has
-// a *QueryError type.
-func (iter *Iter) Close() error {
-	iter.m.Lock()
-	cursorId := iter.op.cursorId
-	iter.op.cursorId = 0
-	err := iter.err
-	iter.m.Unlock()
-	if cursorId == 0 {
-		if err == ErrNotFound {
-			return nil
-		}
-		return err
-	}
-	socket, err := iter.acquireSocket()
-	if err == nil {
-		// TODO Batch kills.
-		err = socket.Query(&killCursorsOp{[]int64{cursorId}})
-		socket.Release()
-	}
-
-	iter.m.Lock()
-	if err != nil && (iter.err == nil || iter.err == ErrNotFound) {
-		iter.err = err
-	} else if iter.err != ErrNotFound {
-		err = iter.err
-	}
-	iter.m.Unlock()
-	return err
-}
-
-// Done returns true only if a follow up Next call is guaranteed
-// to return false.
-//
-// For an iterator created with Tail, Done may return false for
-// an iterator that has no more data. Otherwise it's guaranteed
-// to return false only if there is data or an error happened.
-//
-// Done may block waiting for a pending query to verify whether
-// more data is actually available or not.
-func (iter *Iter) Done() bool {
-	iter.m.Lock()
-	defer iter.m.Unlock()
-
-	for {
-		if iter.docData.Len() > 0 {
-			return false
-		}
-		if iter.docsToReceive > 1 {
-			return true
-		}
-		if iter.docsToReceive > 0 {
-			iter.gotReply.Wait()
-			continue
-		}
-		return iter.op.cursorId == 0
-	}
-}
-
-// Timeout returns true if Next returned false due to a timeout of
-// a tailable cursor. In those cases, Next may be called again to continue
-// the iteration at the previous cursor position.
-func (iter *Iter) Timeout() bool {
-	iter.m.Lock()
-	result := iter.timedout
-	iter.m.Unlock()
-	return result
-}
-
-// Next retrieves the next document from the result set, blocking if necessary.
-// This method will also automatically retrieve another batch of documents from
-// the server when the current one is exhausted, or before that in background
-// if pre-fetching is enabled (see the Query.Prefetch and Session.SetPrefetch
-// methods).
-//
-// Next returns true if a document was successfully unmarshalled onto result,
-// and false at the end of the result set or if an error happened.
-// When Next returns false, the Err method should be called to verify if
-// there was an error during iteration.
-//
-// For example:
-//
-//    iter := collection.Find(nil).Iter()
-//    for iter.Next(&result) {
-//        fmt.Printf("Result: %v\n", result.Id)
-//    }
-//    if err := iter.Close(); err != nil {
-//        return err
-//    }
-//
-func (iter *Iter) Next(result interface{}) bool {
-	iter.m.Lock()
-	iter.timedout = false
-	timeout := time.Time{}
-	for iter.err == nil && iter.docData.Len() == 0 && (iter.docsToReceive > 0 || iter.op.cursorId != 0) {
-		if iter.docsToReceive == 0 {
-			if iter.timeout >= 0 {
-				if timeout.IsZero() {
-					timeout = time.Now().Add(iter.timeout)
-				}
-				if time.Now().After(timeout) {
-					iter.timedout = true
-					iter.m.Unlock()
-					return false
-				}
-			}
-			iter.getMore()
-			if iter.err != nil {
-				break
-			}
-		}
-		iter.gotReply.Wait()
-	}
-
-	// Exhaust available data before reporting any errors.
-	if docData, ok := iter.docData.Pop().([]byte); ok {
-		close := false
-		if iter.limit > 0 {
-			iter.limit--
-			if iter.limit == 0 {
-				if iter.docData.Len() > 0 {
-					iter.m.Unlock()
-					panic(fmt.Errorf("data remains after limit exhausted: %d", iter.docData.Len()))
-				}
-				iter.err = ErrNotFound
-				close = true
-			}
-		}
-		if iter.op.cursorId != 0 && iter.err == nil {
-			iter.docsBeforeMore--
-			if iter.docsBeforeMore == -1 {
-				iter.getMore()
-			}
-		}
-		iter.m.Unlock()
-
-		if close {
-			iter.Close()
-		}
-		err := bson.Unmarshal(docData, result)
-		if err != nil {
-			debugf("Iter %p document unmarshaling failed: %#v", iter, err)
-			iter.m.Lock()
-			if iter.err == nil {
-				iter.err = err
-			}
-			iter.m.Unlock()
-			return false
-		}
-		debugf("Iter %p document unmarshaled: %#v", iter, result)
-		// XXX Only have to check first document for a query error?
-		err = checkQueryError(iter.op.collection, docData)
-		if err != nil {
-			iter.m.Lock()
-			if iter.err == nil {
-				iter.err = err
-			}
-			iter.m.Unlock()
-			return false
-		}
-		return true
-	} else if iter.err != nil {
-		debugf("Iter %p returning false: %s", iter, iter.err)
-		iter.m.Unlock()
-		return false
-	} else if iter.op.cursorId == 0 {
-		iter.err = ErrNotFound
-		debugf("Iter %p exhausted with cursor=0", iter)
-		iter.m.Unlock()
-		return false
-	}
-
-	panic("unreachable")
-}
-
-// All retrieves all documents from the result set into the provided slice
-// and closes the iterator.
-//
-// The result argument must necessarily be the address for a slice. The slice
-// may be nil or previously allocated.
-//
-// WARNING: Obviously, All must not be used with result sets that may be
-// potentially large, since it may consume all memory until the system
-// crashes. Consider building the query with a Limit clause to ensure the
-// result size is bounded.
-//
-// For instance:
-//
-//    var result []struct{ Value int }
-//    iter := collection.Find(nil).Limit(100).Iter()
-//    err := iter.All(&result)
-//    if err != nil {
-//        return err
-//    }
-//
-func (iter *Iter) All(result interface{}) error {
-	resultv := reflect.ValueOf(result)
-	if resultv.Kind() != reflect.Ptr || resultv.Elem().Kind() != reflect.Slice {
-		panic("result argument must be a slice address")
-	}
-	slicev := resultv.Elem()
-	slicev = slicev.Slice(0, slicev.Cap())
-	elemt := slicev.Type().Elem()
-	i := 0
-	for {
-		if slicev.Len() == i {
-			elemp := reflect.New(elemt)
-			if !iter.Next(elemp.Interface()) {
-				break
-			}
-			slicev = reflect.Append(slicev, elemp.Elem())
-			slicev = slicev.Slice(0, slicev.Cap())
-		} else {
-			if !iter.Next(slicev.Index(i).Addr().Interface()) {
-				break
-			}
-		}
-		i++
-	}
-	resultv.Elem().Set(slicev.Slice(0, i))
-	return iter.Close()
-}
-
-// All works like Iter.All.
-func (q *Query) All(result interface{}) error {
-	return q.Iter().All(result)
-}
-
-// The For method is obsolete and will be removed in a future release.
-// See Iter as an elegant replacement.
-func (q *Query) For(result interface{}, f func() error) error {
-	return q.Iter().For(result, f)
-}
-
-// The For method is obsolete and will be removed in a future release.
-// See Iter as an elegant replacement.
-func (iter *Iter) For(result interface{}, f func() error) (err error) {
-	valid := false
-	v := reflect.ValueOf(result)
-	if v.Kind() == reflect.Ptr {
-		v = v.Elem()
-		switch v.Kind() {
-		case reflect.Map, reflect.Ptr, reflect.Interface, reflect.Slice:
-			valid = v.IsNil()
-		}
-	}
-	if !valid {
-		panic("For needs a pointer to nil reference value.  See the documentation.")
-	}
-	zero := reflect.Zero(v.Type())
-	for {
-		v.Set(zero)
-		if !iter.Next(result) {
-			break
-		}
-		err = f()
-		if err != nil {
-			return err
-		}
-	}
-	return iter.Err()
-}
-
-// acquireSocket acquires a socket from the same server that the iterator
-// cursor was obtained from.
-//
-// WARNING: This method must not be called with iter.m locked. Acquiring the
-// socket depends on the cluster sync loop, and the cluster sync loop might
-// attempt actions which cause replyFunc to be called, inducing a deadlock.
-func (iter *Iter) acquireSocket() (*mongoSocket, error) {
-	socket, err := iter.session.acquireSocket(true)
-	if err != nil {
-		return nil, err
-	}
-	if socket.Server() != iter.server {
-		// Socket server changed during iteration. This may happen
-		// with Eventual sessions, if a Refresh is done, or if a
-		// monotonic session gets a write and shifts from secondary
-		// to primary. Our cursor is in a specific server, though.
-		iter.session.m.Lock()
-		sockTimeout := iter.session.sockTimeout
-		iter.session.m.Unlock()
-		socket.Release()
-		socket, _, err = iter.server.AcquireSocket(0, sockTimeout)
-		if err != nil {
-			return nil, err
-		}
-		err := iter.session.socketLogin(socket)
-		if err != nil {
-			socket.Release()
-			return nil, err
-		}
-	}
-	return socket, nil
-}
-
-func (iter *Iter) getMore() {
-	// Increment now so that unlocking the iterator won't cause a
-	// different goroutine to get here as well.
-	iter.docsToReceive++
-	iter.m.Unlock()
-	socket, err := iter.acquireSocket()
-	iter.m.Lock()
-	if err != nil {
-		iter.err = err
-		return
-	}
-	defer socket.Release()
-
-	debugf("Iter %p requesting more documents", iter)
-	if iter.limit > 0 {
-		// The -1 below accounts for the fact docsToReceive was incremented above.
-		limit := iter.limit - int32(iter.docsToReceive-1) - int32(iter.docData.Len())
-		if limit < iter.op.limit {
-			iter.op.limit = limit
-		}
-	}
-	var op interface{}
-	if iter.findCmd {
-		op = iter.getMoreCmd()
-	} else {
-		op = &iter.op
-	}
-	if err := socket.Query(op); err != nil {
-		iter.docsToReceive--
-		iter.err = err
-	}
-}
-
-func (iter *Iter) getMoreCmd() *queryOp {
-	// TODO: Define the query statically in the Iter type, next to getMoreOp.
-	nameDot := strings.Index(iter.op.collection, ".")
-	if nameDot < 0 {
-		panic("invalid query collection name: " + iter.op.collection)
-	}
-
-	getMore := getMoreCmd{
-		CursorId:   iter.op.cursorId,
-		Collection: iter.op.collection[nameDot+1:],
-		BatchSize:  iter.op.limit,
-	}
-
-	var op queryOp
-	op.collection = iter.op.collection[:nameDot] + ".$cmd"
-	op.query = &getMore
-	op.limit = -1
-	op.replyFunc = iter.op.replyFunc
-	return &op
-}
-
-type countCmd struct {
-	Count string
-	Query interface{}
-	Limit int32 ",omitempty"
-	Skip  int32 ",omitempty"
-}
-
-// Count returns the total number of documents in the result set.
-func (q *Query) Count() (n int, err error) {
-	q.m.Lock()
-	session := q.session
-	op := q.op
-	limit := q.limit
-	q.m.Unlock()
-
-	c := strings.Index(op.collection, ".")
-	if c < 0 {
-		return 0, errors.New("Bad collection name: " + op.collection)
-	}
-
-	dbname := op.collection[:c]
-	cname := op.collection[c+1:]
-	query := op.query
-	if query == nil {
-		query = bson.D{}
-	}
-	result := struct{ N int }{}
-	err = session.DB(dbname).Run(countCmd{cname, query, limit, op.skip}, &result)
-	return result.N, err
-}
-
-// Count returns the total number of documents in the collection.
-func (c *Collection) Count() (n int, err error) {
-	return c.Find(nil).Count()
-}
-
-type distinctCmd struct {
-	Collection string "distinct"
-	Key        string
-	Query      interface{} ",omitempty"
-}
-
-// Distinct unmarshals into result the list of distinct values for the given key.
-//
-// For example:
-//
-//     var result []int
-//     err := collection.Find(bson.M{"gender": "F"}).Distinct("age", &result)
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/Aggregation
-//
-func (q *Query) Distinct(key string, result interface{}) error {
-	q.m.Lock()
-	session := q.session
-	op := q.op // Copy.
-	q.m.Unlock()
-
-	c := strings.Index(op.collection, ".")
-	if c < 0 {
-		return errors.New("Bad collection name: " + op.collection)
-	}
-
-	dbname := op.collection[:c]
-	cname := op.collection[c+1:]
-
-	var doc struct{ Values bson.Raw }
-	err := session.DB(dbname).Run(distinctCmd{cname, key, op.query}, &doc)
-	if err != nil {
-		return err
-	}
-	return doc.Values.Unmarshal(result)
-}
-
-type mapReduceCmd struct {
-	Collection string "mapreduce"
-	Map        string ",omitempty"
-	Reduce     string ",omitempty"
-	Finalize   string ",omitempty"
-	Limit      int32  ",omitempty"
-	Out        interface{}
-	Query      interface{} ",omitempty"
-	Sort       interface{} ",omitempty"
-	Scope      interface{} ",omitempty"
-	Verbose    bool        ",omitempty"
-}
-
-type mapReduceResult struct {
-	Results    bson.Raw
-	Result     bson.Raw
-	TimeMillis int64 "timeMillis"
-	Counts     struct{ Input, Emit, Output int }
-	Ok         bool
-	Err        string
-	Timing     *MapReduceTime
-}
-
-type MapReduce struct {
-	Map      string      // Map Javascript function code (required)
-	Reduce   string      // Reduce Javascript function code (required)
-	Finalize string      // Finalize Javascript function code (optional)
-	Out      interface{} // Output collection name or document. If nil, results are inlined into the result parameter.
-	Scope    interface{} // Optional global scope for Javascript functions
-	Verbose  bool
-}
-
-type MapReduceInfo struct {
-	InputCount  int            // Number of documents mapped
-	EmitCount   int            // Number of times reduce called emit
-	OutputCount int            // Number of documents in resulting collection
-	Database    string         // Output database, if results are not inlined
-	Collection  string         // Output collection, if results are not inlined
-	Time        int64          // Time to run the job, in nanoseconds
-	VerboseTime *MapReduceTime // Only defined if Verbose was true
-}
-
-type MapReduceTime struct {
-	Total    int64 // Total time, in nanoseconds
-	Map      int64 "mapTime"  // Time within map function, in nanoseconds
-	EmitLoop int64 "emitLoop" // Time within the emit/map loop, in nanoseconds
-}
-
-// MapReduce executes a map/reduce job for documents covered by the query.
-// That kind of job is suitable for very flexible bulk aggregation of data
-// performed at the server side via Javascript functions.
-//
-// Results from the job may be returned as a result of the query itself
-// through the result parameter in case they'll certainly fit in memory
-// and in a single document.  If there's the possibility that the amount
-// of data might be too large, results must be stored back in an alternative
-// collection or even a separate database, by setting the Out field of the
-// provided MapReduce job.  In that case, provide nil as the result parameter.
-//
-// These are some of the ways to set Out:
-//
-//     nil
-//         Inline results into the result parameter.
-//
-//     bson.M{"replace": "mycollection"}
-//         The output will be inserted into a collection which replaces any
-//         existing collection with the same name.
-//
-//     bson.M{"merge": "mycollection"}
-//         This option will merge new data into the old output collection. In
-//         other words, if the same key exists in both the result set and the
-//         old collection, the new key will overwrite the old one.
-//
-//     bson.M{"reduce": "mycollection"}
-//         If documents exist for a given key in the result set and in the old
-//         collection, then a reduce operation (using the specified reduce
-//         function) will be performed on the two values and the result will be
-//         written to the output collection. If a finalize function was
-//         provided, this will be run after the reduce as well.
-//
-//     bson.M{...., "db": "mydb"}
-//         Any of the above options can have the "db" key included for doing
-//         the respective action in a separate database.
-//
-// The following is a trivial example which will count the number of
-// occurrences of a field named n on each document in a collection, and
-// will return results inline:
-//
-//     job := &mgo.MapReduce{
-//             Map:      "function() { emit(this.n, 1) }",
-//             Reduce:   "function(key, values) { return Array.sum(values) }",
-//     }
-//     var result []struct { Id int "_id"; Value int }
-//     _, err := collection.Find(nil).MapReduce(job, &result)
-//     if err != nil {
-//         return err
-//     }
-//     for _, item := range result {
-//         fmt.Println(item.Value)
-//     }
-//
-// This function is compatible with MongoDB 1.7.4+.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/MapReduce
-//
-func (q *Query) MapReduce(job *MapReduce, result interface{}) (info *MapReduceInfo, err error) {
-	q.m.Lock()
-	session := q.session
-	op := q.op // Copy.
-	limit := q.limit
-	q.m.Unlock()
-
-	c := strings.Index(op.collection, ".")
-	if c < 0 {
-		return nil, errors.New("Bad collection name: " + op.collection)
-	}
-
-	dbname := op.collection[:c]
-	cname := op.collection[c+1:]
-
-	cmd := mapReduceCmd{
-		Collection: cname,
-		Map:        job.Map,
-		Reduce:     job.Reduce,
-		Finalize:   job.Finalize,
-		Out:        fixMROut(job.Out),
-		Scope:      job.Scope,
-		Verbose:    job.Verbose,
-		Query:      op.query,
-		Sort:       op.options.OrderBy,
-		Limit:      limit,
-	}
-
-	if cmd.Out == nil {
-		cmd.Out = bson.D{{"inline", 1}}
-	}
-
-	var doc mapReduceResult
-	err = session.DB(dbname).Run(&cmd, &doc)
-	if err != nil {
-		return nil, err
-	}
-	if doc.Err != "" {
-		return nil, errors.New(doc.Err)
-	}
-
-	info = &MapReduceInfo{
-		InputCount:  doc.Counts.Input,
-		EmitCount:   doc.Counts.Emit,
-		OutputCount: doc.Counts.Output,
-		Time:        doc.TimeMillis * 1e6,
-	}
-
-	if doc.Result.Kind == 0x02 {
-		err = doc.Result.Unmarshal(&info.Collection)
-		info.Database = dbname
-	} else if doc.Result.Kind == 0x03 {
-		var v struct{ Collection, Db string }
-		err = doc.Result.Unmarshal(&v)
-		info.Collection = v.Collection
-		info.Database = v.Db
-	}
-
-	if doc.Timing != nil {
-		info.VerboseTime = doc.Timing
-		info.VerboseTime.Total *= 1e6
-		info.VerboseTime.Map *= 1e6
-		info.VerboseTime.EmitLoop *= 1e6
-	}
-
-	if err != nil {
-		return nil, err
-	}
-	if result != nil {
-		return info, doc.Results.Unmarshal(result)
-	}
-	return info, nil
-}
-
-// The "out" option in the MapReduce command must be ordered. This was
-// found after the implementation was accepting maps for a long time,
-// so rather than breaking the API, we'll fix the order if necessary.
-// Details about the order requirement may be seen in MongoDB's code:
-//
-//     http://goo.gl/L8jwJX
-//
-func fixMROut(out interface{}) interface{} {
-	outv := reflect.ValueOf(out)
-	if outv.Kind() != reflect.Map || outv.Type().Key() != reflect.TypeOf("") {
-		return out
-	}
-	outs := make(bson.D, outv.Len())
-
-	outTypeIndex := -1
-	for i, k := range outv.MapKeys() {
-		ks := k.String()
-		outs[i].Name = ks
-		outs[i].Value = outv.MapIndex(k).Interface()
-		switch ks {
-		case "normal", "replace", "merge", "reduce", "inline":
-			outTypeIndex = i
-		}
-	}
-	if outTypeIndex > 0 {
-		outs[0], outs[outTypeIndex] = outs[outTypeIndex], outs[0]
-	}
-	return outs
-}
-
-// Change holds fields for running a findAndModify MongoDB command via
-// the Query.Apply method.
-type Change struct {
-	Update    interface{} // The update document
-	Upsert    bool        // Whether to insert in case the document isn't found
-	Remove    bool        // Whether to remove the document found rather than updating
-	ReturnNew bool        // Should the modified document be returned rather than the old one
-}
-
-type findModifyCmd struct {
-	Collection                  string      "findAndModify"
-	Query, Update, Sort, Fields interface{} ",omitempty"
-	Upsert, Remove, New         bool        ",omitempty"
-}
-
-type valueResult struct {
-	Value     bson.Raw
-	LastError LastError "lastErrorObject"
-}
-
-// Apply runs the findAndModify MongoDB command, which allows updating, upserting
-// or removing a document matching a query and atomically returning either the old
-// version (the default) or the new version of the document (when ReturnNew is true).
-// If no objects are found Apply returns ErrNotFound.
-//
-// The Sort and Select query methods affect the result of Apply.  In case
-// multiple documents match the query, Sort enables selecting which document to
-// act upon by ordering it first.  Select enables retrieving only a selection
-// of fields of the new or old document.
-//
-// This simple example increments a counter and prints its new value:
-//
-//     change := mgo.Change{
-//             Update: bson.M{"$inc": bson.M{"n": 1}},
-//             ReturnNew: true,
-//     }
-//     info, err = col.Find(M{"_id": id}).Apply(change, &doc)
-//     fmt.Println(doc.N)
-//
-// This method depends on MongoDB >= 2.0 to work properly.
-//
-// Relevant documentation:
-//
-//     http://www.mongodb.org/display/DOCS/findAndModify+Command
-//     http://www.mongodb.org/display/DOCS/Updating
-//     http://www.mongodb.org/display/DOCS/Atomic+Operations
-//
-func (q *Query) Apply(change Change, result interface{}) (info *ChangeInfo, err error) {
-	q.m.Lock()
-	session := q.session
-	op := q.op // Copy.
-	q.m.Unlock()
-
-	c := strings.Index(op.collection, ".")
-	if c < 0 {
-		return nil, errors.New("bad collection name: " + op.collection)
-	}
-
-	dbname := op.collection[:c]
-	cname := op.collection[c+1:]
-
-	cmd := findModifyCmd{
-		Collection: cname,
-		Update:     change.Update,
-		Upsert:     change.Upsert,
-		Remove:     change.Remove,
-		New:        change.ReturnNew,
-		Query:      op.query,
-		Sort:       op.options.OrderBy,
-		Fields:     op.selector,
-	}
-
-	session = session.Clone()
-	defer session.Close()
-	session.SetMode(Strong, false)
-
-	var doc valueResult
-	for i := 0; i < maxUpsertRetries; i++ {
-		err = session.DB(dbname).Run(&cmd, &doc)
-		if err == nil {
-			break
-		}
-		if change.Upsert && IsDup(err) && i+1 < maxUpsertRetries {
-			// Retry duplicate key errors on upserts.
-			// https://docs.mongodb.com/v3.2/reference/method/db.collection.update/#use-unique-indexes
-			continue
-		}
-		if qerr, ok := err.(*QueryError); ok && qerr.Message == "No matching object found" {
-			return nil, ErrNotFound
-		}
-		return nil, err
-	}
-	if doc.LastError.N == 0 {
-		return nil, ErrNotFound
-	}
-	if doc.Value.Kind != 0x0A && result != nil {
-		err = doc.Value.Unmarshal(result)
-		if err != nil {
-			return nil, err
-		}
-	}
-	info = &ChangeInfo{}
-	lerr := &doc.LastError
-	if lerr.UpdatedExisting {
-		info.Updated = lerr.N
-		info.Matched = lerr.N
-	} else if change.Remove {
-		info.Removed = lerr.N
-		info.Matched = lerr.N
-	} else if change.Upsert {
-		info.UpsertedId = lerr.UpsertedId
-	}
-	return info, nil
-}
-
-// The BuildInfo type encapsulates details about the running MongoDB server.
-//
-// Note that the VersionArray field was introduced in MongoDB 2.0+, but it is
-// internally assembled from the Version information for previous versions.
-// In both cases, VersionArray is guaranteed to have at least 4 entries.
-type BuildInfo struct {
-	Version        string
-	VersionArray   []int  `bson:"versionArray"` // On MongoDB 2.0+; assembled from Version otherwise
-	GitVersion     string `bson:"gitVersion"`
-	OpenSSLVersion string `bson:"OpenSSLVersion"`
-	SysInfo        string `bson:"sysInfo"` // Deprecated and empty on MongoDB 3.2+.
-	Bits           int
-	Debug          bool
-	MaxObjectSize  int `bson:"maxBsonObjectSize"`
-}
-
-// VersionAtLeast returns whether the BuildInfo version is greater than or
-// equal to the provided version number. If more than one number is
-// provided, numbers will be considered as major, minor, and so on.
-func (bi *BuildInfo) VersionAtLeast(version ...int) bool {
-	for i, vi := range version {
-		if i == len(bi.VersionArray) {
-			return false
-		}
-		if bivi := bi.VersionArray[i]; bivi != vi {
-			return bivi >= vi
-		}
-	}
-	return true
-}
-
-// BuildInfo retrieves the version and other details about the
-// running MongoDB server.
-func (s *Session) BuildInfo() (info BuildInfo, err error) {
-	err = s.Run(bson.D{{"buildInfo", "1"}}, &info)
-	if len(info.VersionArray) == 0 {
-		for _, a := range strings.Split(info.Version, ".") {
-			i, err := strconv.Atoi(a)
-			if err != nil {
-				break
-			}
-			info.VersionArray = append(info.VersionArray, i)
-		}
-	}
-	for len(info.VersionArray) < 4 {
-		info.VersionArray = append(info.VersionArray, 0)
-	}
-	if i := strings.IndexByte(info.GitVersion, ' '); i >= 0 {
-		// Strip off the " modules: enterprise" suffix. This is a _git version_.
-		// That information may be moved to another field if people need it.
-		info.GitVersion = info.GitVersion[:i]
-	}
-	if info.SysInfo == "deprecated" {
-		info.SysInfo = ""
-	}
-	return
-}
-
-// ---------------------------------------------------------------------------
-// Internal session handling helpers.
-
-func (s *Session) acquireSocket(slaveOk bool) (*mongoSocket, error) {
-
-	// Read-only lock to check for previously reserved socket.
-	s.m.RLock()
-	// If there is a slave socket reserved and its use is acceptable, take it as long
-	// as there isn't a master socket which would be preferred by the read preference mode.
-	if s.slaveSocket != nil && s.slaveOk && slaveOk && (s.masterSocket == nil || s.consistency != PrimaryPreferred && s.consistency != Monotonic) {
-		socket := s.slaveSocket
-		socket.Acquire()
-		s.m.RUnlock()
-		return socket, nil
-	}
-	if s.masterSocket != nil {
-		socket := s.masterSocket
-		socket.Acquire()
-		s.m.RUnlock()
-		return socket, nil
-	}
-	s.m.RUnlock()
-
-	// No go.  We may have to request a new socket and change the session,
-	// so try again but with an exclusive lock now.
-	s.m.Lock()
-	defer s.m.Unlock()
-
-	if s.slaveSocket != nil && s.slaveOk && slaveOk && (s.masterSocket == nil || s.consistency != PrimaryPreferred && s.consistency != Monotonic) {
-		s.slaveSocket.Acquire()
-		return s.slaveSocket, nil
-	}
-	if s.masterSocket != nil {
-		s.masterSocket.Acquire()
-		return s.masterSocket, nil
-	}
-
-	// Still not good.  We need a new socket.
-	sock, err := s.cluster().AcquireSocket(s.consistency, slaveOk && s.slaveOk, s.syncTimeout, s.sockTimeout, s.queryConfig.op.serverTags, s.poolLimit)
-	if err != nil {
-		return nil, err
-	}
-
-	// Authenticate the new socket.
-	if err = s.socketLogin(sock); err != nil {
-		sock.Release()
-		return nil, err
-	}
-
-	// Keep track of the new socket, if necessary.
-	// Note that, as a special case, if the Eventual session was
-	// not refreshed (s.slaveSocket != nil), it means the developer
-	// asked to preserve an existing reserved socket, so we'll
-	// keep a master one around too before a Refresh happens.
-	if s.consistency != Eventual || s.slaveSocket != nil {
-		s.setSocket(sock)
-	}
-
-	// Switch over a Monotonic session to the master.
-	if !slaveOk && s.consistency == Monotonic {
-		s.slaveOk = false
-	}
-
-	return sock, nil
-}
-
-// setSocket binds socket to this section.
-func (s *Session) setSocket(socket *mongoSocket) {
-	info := socket.Acquire()
-	if info.Master {
-		if s.masterSocket != nil {
-			panic("setSocket(master) with existing master socket reserved")
-		}
-		s.masterSocket = socket
-	} else {
-		if s.slaveSocket != nil {
-			panic("setSocket(slave) with existing slave socket reserved")
-		}
-		s.slaveSocket = socket
-	}
-}
-
-// unsetSocket releases any slave and/or master sockets reserved.
-func (s *Session) unsetSocket() {
-	if s.masterSocket != nil {
-		s.masterSocket.Release()
-	}
-	if s.slaveSocket != nil {
-		s.slaveSocket.Release()
-	}
-	s.masterSocket = nil
-	s.slaveSocket = nil
-}
-
-func (iter *Iter) replyFunc() replyFunc {
-	return func(err error, op *replyOp, docNum int, docData []byte) {
-		iter.m.Lock()
-		iter.docsToReceive--
-		if err != nil {
-			iter.err = err
-			debugf("Iter %p received an error: %s", iter, err.Error())
-		} else if docNum == -1 {
-			debugf("Iter %p received no documents (cursor=%d).", iter, op.cursorId)
-			if op != nil && op.cursorId != 0 {
-				// It's a tailable cursor.
-				iter.op.cursorId = op.cursorId
-			} else if op != nil && op.cursorId == 0 && op.flags&1 == 1 {
-				// Cursor likely timed out.
-				iter.err = ErrCursor
-			} else {
-				iter.err = ErrNotFound
-			}
-		} else if iter.findCmd {
-			debugf("Iter %p received reply document %d/%d (cursor=%d)", iter, docNum+1, int(op.replyDocs), op.cursorId)
-			var findReply struct {
-				Ok     bool
-				Code   int
-				Errmsg string
-				Cursor cursorData
-			}
-			if err := bson.Unmarshal(docData, &findReply); err != nil {
-				iter.err = err
-			} else if !findReply.Ok && findReply.Errmsg != "" {
-				iter.err = &QueryError{Code: findReply.Code, Message: findReply.Errmsg}
-			} else if len(findReply.Cursor.FirstBatch) == 0 && len(findReply.Cursor.NextBatch) == 0 {
-				iter.err = ErrNotFound
-			} else {
-				batch := findReply.Cursor.FirstBatch
-				if len(batch) == 0 {
-					batch = findReply.Cursor.NextBatch
-				}
-				rdocs := len(batch)
-				for _, raw := range batch {
-					iter.docData.Push(raw.Data)
-				}
-				iter.docsToReceive = 0
-				docsToProcess := iter.docData.Len()
-				if iter.limit == 0 || int32(docsToProcess) < iter.limit {
-					iter.docsBeforeMore = docsToProcess - int(iter.prefetch*float64(rdocs))
-				} else {
-					iter.docsBeforeMore = -1
-				}
-				iter.op.cursorId = findReply.Cursor.Id
-			}
-		} else {
-			rdocs := int(op.replyDocs)
-			if docNum == 0 {
-				iter.docsToReceive += rdocs - 1
-				docsToProcess := iter.docData.Len() + rdocs
-				if iter.limit == 0 || int32(docsToProcess) < iter.limit {
-					iter.docsBeforeMore = docsToProcess - int(iter.prefetch*float64(rdocs))
-				} else {
-					iter.docsBeforeMore = -1
-				}
-				iter.op.cursorId = op.cursorId
-			}
-			debugf("Iter %p received reply document %d/%d (cursor=%d)", iter, docNum+1, rdocs, op.cursorId)
-			iter.docData.Push(docData)
-		}
-		iter.gotReply.Broadcast()
-		iter.m.Unlock()
-	}
-}
-
-type writeCmdResult struct {
-	Ok        bool
-	N         int
-	NModified int `bson:"nModified"`
-	Upserted  []struct {
-		Index int
-		Id    interface{} `_id`
-	}
-	ConcernError writeConcernError `bson:"writeConcernError"`
-	Errors       []writeCmdError   `bson:"writeErrors"`
-}
-
-type writeConcernError struct {
-	Code   int
-	ErrMsg string
-}
-
-type writeCmdError struct {
-	Index  int
-	Code   int
-	ErrMsg string
-}
-
-func (r *writeCmdResult) BulkErrorCases() []BulkErrorCase {
-	ecases := make([]BulkErrorCase, len(r.Errors))
-	for i, err := range r.Errors {
-		ecases[i] = BulkErrorCase{err.Index, &QueryError{Code: err.Code, Message: err.ErrMsg}}
-	}
-	return ecases
-}
-
-// writeOp runs the given modifying operation, potentially followed up
-// by a getLastError command in case the session is in safe mode.  The
-// LastError result is made available in lerr, and if lerr.Err is set it
-// will also be returned as err.
-func (c *Collection) writeOp(op interface{}, ordered bool) (lerr *LastError, err error) {
-	s := c.Database.Session
-	socket, err := s.acquireSocket(c.Database.Name == "local")
-	if err != nil {
-		return nil, err
-	}
-	defer socket.Release()
-
-	s.m.RLock()
-	safeOp := s.safeOp
-	bypassValidation := s.bypassValidation
-	s.m.RUnlock()
-
-	if socket.ServerInfo().MaxWireVersion >= 2 {
-		// Servers with a more recent write protocol benefit from write commands.
-		if op, ok := op.(*insertOp); ok && len(op.documents) > 1000 {
-			var lerr LastError
-
-			// Maximum batch size is 1000. Must split out in separate operations for compatibility.
-			all := op.documents
-			for i := 0; i < len(all); i += 1000 {
-				l := i + 1000
-				if l > len(all) {
-					l = len(all)
-				}
-				op.documents = all[i:l]
-				oplerr, err := c.writeOpCommand(socket, safeOp, op, ordered, bypassValidation)
-				lerr.N += oplerr.N
-				lerr.modified += oplerr.modified
-				if err != nil {
-					for ei := range oplerr.ecases {
-						oplerr.ecases[ei].Index += i
-					}
-					lerr.ecases = append(lerr.ecases, oplerr.ecases...)
-					if op.flags&1 == 0 {
-						return &lerr, err
-					}
-				}
-			}
-			if len(lerr.ecases) != 0 {
-				return &lerr, lerr.ecases[0].Err
-			}
-			return &lerr, nil
-		}
-		return c.writeOpCommand(socket, safeOp, op, ordered, bypassValidation)
-	} else if updateOps, ok := op.(bulkUpdateOp); ok {
-		var lerr LastError
-		for i, updateOp := range updateOps {
-			oplerr, err := c.writeOpQuery(socket, safeOp, updateOp, ordered)
-			lerr.N += oplerr.N
-			lerr.modified += oplerr.modified
-			if err != nil {
-				lerr.ecases = append(lerr.ecases, BulkErrorCase{i, err})
-				if ordered {
-					break
-				}
-			}
-		}
-		if len(lerr.ecases) != 0 {
-			return &lerr, lerr.ecases[0].Err
-		}
-		return &lerr, nil
-	} else if deleteOps, ok := op.(bulkDeleteOp); ok {
-		var lerr LastError
-		for i, deleteOp := range deleteOps {
-			oplerr, err := c.writeOpQuery(socket, safeOp, deleteOp, ordered)
-			lerr.N += oplerr.N
-			lerr.modified += oplerr.modified
-			if err != nil {
-				lerr.ecases = append(lerr.ecases, BulkErrorCase{i, err})
-				if ordered {
-					break
-				}
-			}
-		}
-		if len(lerr.ecases) != 0 {
-			return &lerr, lerr.ecases[0].Err
-		}
-		return &lerr, nil
-	}
-	return c.writeOpQuery(socket, safeOp, op, ordered)
-}
-
-func (c *Collection) writeOpQuery(socket *mongoSocket, safeOp *queryOp, op interface{}, ordered bool) (lerr *LastError, err error) {
-	if safeOp == nil {
-		return nil, socket.Query(op)
-	}
-
-	var mutex sync.Mutex
-	var replyData []byte
-	var replyErr error
-	mutex.Lock()
-	query := *safeOp // Copy the data.
-	query.collection = c.Database.Name + ".$cmd"
-	query.replyFunc = func(err error, reply *replyOp, docNum int, docData []byte) {
-		replyData = docData
-		replyErr = err
-		mutex.Unlock()
-	}
-	err = socket.Query(op, &query)
-	if err != nil {
-		return nil, err
-	}
-	mutex.Lock() // Wait.
-	if replyErr != nil {
-		return nil, replyErr // XXX TESTME
-	}
-	if hasErrMsg(replyData) {
-		// Looks like getLastError itself failed.
-		err = checkQueryError(query.collection, replyData)
-		if err != nil {
-			return nil, err
-		}
-	}
-	result := &LastError{}
-	bson.Unmarshal(replyData, &result)
-	debugf("Result from writing query: %#v", result)
-	if result.Err != "" {
-		result.ecases = []BulkErrorCase{{Index: 0, Err: result}}
-		if insert, ok := op.(*insertOp); ok && len(insert.documents) > 1 {
-			result.ecases[0].Index = -1
-		}
-		return result, result
-	}
-	// With MongoDB <2.6 we don't know how many actually changed, so make it the same as matched.
-	result.modified = result.N
-	return result, nil
-}
-
-func (c *Collection) writeOpCommand(socket *mongoSocket, safeOp *queryOp, op interface{}, ordered, bypassValidation bool) (lerr *LastError, err error) {
-	var writeConcern interface{}
-	if safeOp == nil {
-		writeConcern = bson.D{{"w", 0}}
-	} else {
-		writeConcern = safeOp.query.(*getLastError)
-	}
-
-	var cmd bson.D
-	switch op := op.(type) {
-	case *insertOp:
-		// http://docs.mongodb.org/manual/reference/command/insert
-		cmd = bson.D{
-			{"insert", c.Name},
-			{"documents", op.documents},
-			{"writeConcern", writeConcern},
-			{"ordered", op.flags&1 == 0},
-		}
-	case *updateOp:
-		// http://docs.mongodb.org/manual/reference/command/update
-		cmd = bson.D{
-			{"update", c.Name},
-			{"updates", []interface{}{op}},
-			{"writeConcern", writeConcern},
-			{"ordered", ordered},
-		}
-	case bulkUpdateOp:
-		// http://docs.mongodb.org/manual/reference/command/update
-		cmd = bson.D{
-			{"update", c.Name},
-			{"updates", op},
-			{"writeConcern", writeConcern},
-			{"ordered", ordered},
-		}
-	case *deleteOp:
-		// http://docs.mongodb.org/manual/reference/command/delete
-		cmd = bson.D{
-			{"delete", c.Name},
-			{"deletes", []interface{}{op}},
-			{"writeConcern", writeConcern},
-			{"ordered", ordered},
-		}
-	case bulkDeleteOp:
-		// http://docs.mongodb.org/manual/reference/command/delete
-		cmd = bson.D{
-			{"delete", c.Name},
-			{"deletes", op},
-			{"writeConcern", writeConcern},
-			{"ordered", ordered},
-		}
-	}
-	if bypassValidation {
-		cmd = append(cmd, bson.DocElem{"bypassDocumentValidation", true})
-	}
-
-	var result writeCmdResult
-	err = c.Database.run(socket, cmd, &result)
-	debugf("Write command result: %#v (err=%v)", result, err)
-	ecases := result.BulkErrorCases()
-	lerr = &LastError{
-		UpdatedExisting: result.N > 0 && len(result.Upserted) == 0,
-		N:               result.N,
-
-		modified: result.NModified,
-		ecases:   ecases,
-	}
-	if len(result.Upserted) > 0 {
-		lerr.UpsertedId = result.Upserted[0].Id
-	}
-	if len(result.Errors) > 0 {
-		e := result.Errors[0]
-		lerr.Code = e.Code
-		lerr.Err = e.ErrMsg
-		err = lerr
-	} else if result.ConcernError.Code != 0 {
-		e := result.ConcernError
-		lerr.Code = e.Code
-		lerr.Err = e.ErrMsg
-		err = lerr
-	}
-
-	if err == nil && safeOp == nil {
-		return nil, nil
-	}
-	return lerr, err
-}
-
-func hasErrMsg(d []byte) bool {
-	l := len(d)
-	for i := 0; i+8 < l; i++ {
-		if d[i] == '\x02' && d[i+1] == 'e' && d[i+2] == 'r' && d[i+3] == 'r' && d[i+4] == 'm' && d[i+5] == 's' && d[i+6] == 'g' && d[i+7] == '\x00' {
-			return true
-		}
-	}
-	return false
-}
diff --git a/vendor/gopkg.in/mgo.v2/socket.go b/vendor/gopkg.in/mgo.v2/socket.go
deleted file mode 100644
index 8891dd5..0000000
--- a/vendor/gopkg.in/mgo.v2/socket.go
+++ /dev/null
@@ -1,707 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"errors"
-	"fmt"
-	"net"
-	"sync"
-	"time"
-
-	"gopkg.in/mgo.v2/bson"
-)
-
-type replyFunc func(err error, reply *replyOp, docNum int, docData []byte)
-
-type mongoSocket struct {
-	sync.Mutex
-	server        *mongoServer // nil when cached
-	conn          net.Conn
-	timeout       time.Duration
-	addr          string // For debugging only.
-	nextRequestId uint32
-	replyFuncs    map[uint32]replyFunc
-	references    int
-	creds         []Credential
-	logout        []Credential
-	cachedNonce   string
-	gotNonce      sync.Cond
-	dead          error
-	serverInfo    *mongoServerInfo
-}
-
-type queryOpFlags uint32
-
-const (
-	_ queryOpFlags = 1 << iota
-	flagTailable
-	flagSlaveOk
-	flagLogReplay
-	flagNoCursorTimeout
-	flagAwaitData
-)
-
-type queryOp struct {
-	collection string
-	query      interface{}
-	skip       int32
-	limit      int32
-	selector   interface{}
-	flags      queryOpFlags
-	replyFunc  replyFunc
-
-	mode       Mode
-	options    queryWrapper
-	hasOptions bool
-	serverTags []bson.D
-}
-
-type queryWrapper struct {
-	Query          interface{} "$query"
-	OrderBy        interface{} "$orderby,omitempty"
-	Hint           interface{} "$hint,omitempty"
-	Explain        bool        "$explain,omitempty"
-	Snapshot       bool        "$snapshot,omitempty"
-	ReadPreference bson.D      "$readPreference,omitempty"
-	MaxScan        int         "$maxScan,omitempty"
-	MaxTimeMS      int         "$maxTimeMS,omitempty"
-	Comment        string      "$comment,omitempty"
-}
-
-func (op *queryOp) finalQuery(socket *mongoSocket) interface{} {
-	if op.flags&flagSlaveOk != 0 && socket.ServerInfo().Mongos {
-		var modeName string
-		switch op.mode {
-		case Strong:
-			modeName = "primary"
-		case Monotonic, Eventual:
-			modeName = "secondaryPreferred"
-		case PrimaryPreferred:
-			modeName = "primaryPreferred"
-		case Secondary:
-			modeName = "secondary"
-		case SecondaryPreferred:
-			modeName = "secondaryPreferred"
-		case Nearest:
-			modeName = "nearest"
-		default:
-			panic(fmt.Sprintf("unsupported read mode: %d", op.mode))
-		}
-		op.hasOptions = true
-		op.options.ReadPreference = make(bson.D, 0, 2)
-		op.options.ReadPreference = append(op.options.ReadPreference, bson.DocElem{"mode", modeName})
-		if len(op.serverTags) > 0 {
-			op.options.ReadPreference = append(op.options.ReadPreference, bson.DocElem{"tags", op.serverTags})
-		}
-	}
-	if op.hasOptions {
-		if op.query == nil {
-			var empty bson.D
-			op.options.Query = empty
-		} else {
-			op.options.Query = op.query
-		}
-		debugf("final query is %#v\n", &op.options)
-		return &op.options
-	}
-	return op.query
-}
-
-type getMoreOp struct {
-	collection string
-	limit      int32
-	cursorId   int64
-	replyFunc  replyFunc
-}
-
-type replyOp struct {
-	flags     uint32
-	cursorId  int64
-	firstDoc  int32
-	replyDocs int32
-}
-
-type insertOp struct {
-	collection string        // "database.collection"
-	documents  []interface{} // One or more documents to insert
-	flags      uint32
-}
-
-type updateOp struct {
-	Collection string      `bson:"-"` // "database.collection"
-	Selector   interface{} `bson:"q"`
-	Update     interface{} `bson:"u"`
-	Flags      uint32      `bson:"-"`
-	Multi      bool        `bson:"multi,omitempty"`
-	Upsert     bool        `bson:"upsert,omitempty"`
-}
-
-type deleteOp struct {
-	Collection string      `bson:"-"` // "database.collection"
-	Selector   interface{} `bson:"q"`
-	Flags      uint32      `bson:"-"`
-	Limit      int         `bson:"limit"`
-}
-
-type killCursorsOp struct {
-	cursorIds []int64
-}
-
-type requestInfo struct {
-	bufferPos int
-	replyFunc replyFunc
-}
-
-func newSocket(server *mongoServer, conn net.Conn, timeout time.Duration) *mongoSocket {
-	socket := &mongoSocket{
-		conn:       conn,
-		addr:       server.Addr,
-		server:     server,
-		replyFuncs: make(map[uint32]replyFunc),
-	}
-	socket.gotNonce.L = &socket.Mutex
-	if err := socket.InitialAcquire(server.Info(), timeout); err != nil {
-		panic("newSocket: InitialAcquire returned error: " + err.Error())
-	}
-	stats.socketsAlive(+1)
-	debugf("Socket %p to %s: initialized", socket, socket.addr)
-	socket.resetNonce()
-	go socket.readLoop()
-	return socket
-}
-
-// Server returns the server that the socket is associated with.
-// It returns nil while the socket is cached in its respective server.
-func (socket *mongoSocket) Server() *mongoServer {
-	socket.Lock()
-	server := socket.server
-	socket.Unlock()
-	return server
-}
-
-// ServerInfo returns details for the server at the time the socket
-// was initially acquired.
-func (socket *mongoSocket) ServerInfo() *mongoServerInfo {
-	socket.Lock()
-	serverInfo := socket.serverInfo
-	socket.Unlock()
-	return serverInfo
-}
-
-// InitialAcquire obtains the first reference to the socket, either
-// right after the connection is made or once a recycled socket is
-// being put back in use.
-func (socket *mongoSocket) InitialAcquire(serverInfo *mongoServerInfo, timeout time.Duration) error {
-	socket.Lock()
-	if socket.references > 0 {
-		panic("Socket acquired out of cache with references")
-	}
-	if socket.dead != nil {
-		dead := socket.dead
-		socket.Unlock()
-		return dead
-	}
-	socket.references++
-	socket.serverInfo = serverInfo
-	socket.timeout = timeout
-	stats.socketsInUse(+1)
-	stats.socketRefs(+1)
-	socket.Unlock()
-	return nil
-}
-
-// Acquire obtains an additional reference to the socket.
-// The socket will only be recycled when it's released as many
-// times as it's been acquired.
-func (socket *mongoSocket) Acquire() (info *mongoServerInfo) {
-	socket.Lock()
-	if socket.references == 0 {
-		panic("Socket got non-initial acquire with references == 0")
-	}
-	// We'll track references to dead sockets as well.
-	// Caller is still supposed to release the socket.
-	socket.references++
-	stats.socketRefs(+1)
-	serverInfo := socket.serverInfo
-	socket.Unlock()
-	return serverInfo
-}
-
-// Release decrements a socket reference. The socket will be
-// recycled once its released as many times as it's been acquired.
-func (socket *mongoSocket) Release() {
-	socket.Lock()
-	if socket.references == 0 {
-		panic("socket.Release() with references == 0")
-	}
-	socket.references--
-	stats.socketRefs(-1)
-	if socket.references == 0 {
-		stats.socketsInUse(-1)
-		server := socket.server
-		socket.Unlock()
-		socket.LogoutAll()
-		// If the socket is dead server is nil.
-		if server != nil {
-			server.RecycleSocket(socket)
-		}
-	} else {
-		socket.Unlock()
-	}
-}
-
-// SetTimeout changes the timeout used on socket operations.
-func (socket *mongoSocket) SetTimeout(d time.Duration) {
-	socket.Lock()
-	socket.timeout = d
-	socket.Unlock()
-}
-
-type deadlineType int
-
-const (
-	readDeadline  deadlineType = 1
-	writeDeadline deadlineType = 2
-)
-
-func (socket *mongoSocket) updateDeadline(which deadlineType) {
-	var when time.Time
-	if socket.timeout > 0 {
-		when = time.Now().Add(socket.timeout)
-	}
-	whichstr := ""
-	switch which {
-	case readDeadline | writeDeadline:
-		whichstr = "read/write"
-		socket.conn.SetDeadline(when)
-	case readDeadline:
-		whichstr = "read"
-		socket.conn.SetReadDeadline(when)
-	case writeDeadline:
-		whichstr = "write"
-		socket.conn.SetWriteDeadline(when)
-	default:
-		panic("invalid parameter to updateDeadline")
-	}
-	debugf("Socket %p to %s: updated %s deadline to %s ahead (%s)", socket, socket.addr, whichstr, socket.timeout, when)
-}
-
-// Close terminates the socket use.
-func (socket *mongoSocket) Close() {
-	socket.kill(errors.New("Closed explicitly"), false)
-}
-
-func (socket *mongoSocket) kill(err error, abend bool) {
-	socket.Lock()
-	if socket.dead != nil {
-		debugf("Socket %p to %s: killed again: %s (previously: %s)", socket, socket.addr, err.Error(), socket.dead.Error())
-		socket.Unlock()
-		return
-	}
-	logf("Socket %p to %s: closing: %s (abend=%v)", socket, socket.addr, err.Error(), abend)
-	socket.dead = err
-	socket.conn.Close()
-	stats.socketsAlive(-1)
-	replyFuncs := socket.replyFuncs
-	socket.replyFuncs = make(map[uint32]replyFunc)
-	server := socket.server
-	socket.server = nil
-	socket.gotNonce.Broadcast()
-	socket.Unlock()
-	for _, replyFunc := range replyFuncs {
-		logf("Socket %p to %s: notifying replyFunc of closed socket: %s", socket, socket.addr, err.Error())
-		replyFunc(err, nil, -1, nil)
-	}
-	if abend {
-		server.AbendSocket(socket)
-	}
-}
-
-func (socket *mongoSocket) SimpleQuery(op *queryOp) (data []byte, err error) {
-	var wait, change sync.Mutex
-	var replyDone bool
-	var replyData []byte
-	var replyErr error
-	wait.Lock()
-	op.replyFunc = func(err error, reply *replyOp, docNum int, docData []byte) {
-		change.Lock()
-		if !replyDone {
-			replyDone = true
-			replyErr = err
-			if err == nil {
-				replyData = docData
-			}
-		}
-		change.Unlock()
-		wait.Unlock()
-	}
-	err = socket.Query(op)
-	if err != nil {
-		return nil, err
-	}
-	wait.Lock()
-	change.Lock()
-	data = replyData
-	err = replyErr
-	change.Unlock()
-	return data, err
-}
-
-func (socket *mongoSocket) Query(ops ...interface{}) (err error) {
-
-	if lops := socket.flushLogout(); len(lops) > 0 {
-		ops = append(lops, ops...)
-	}
-
-	buf := make([]byte, 0, 256)
-
-	// Serialize operations synchronously to avoid interrupting
-	// other goroutines while we can't really be sending data.
-	// Also, record id positions so that we can compute request
-	// ids at once later with the lock already held.
-	requests := make([]requestInfo, len(ops))
-	requestCount := 0
-
-	for _, op := range ops {
-		debugf("Socket %p to %s: serializing op: %#v", socket, socket.addr, op)
-		if qop, ok := op.(*queryOp); ok {
-			if cmd, ok := qop.query.(*findCmd); ok {
-				debugf("Socket %p to %s: find command: %#v", socket, socket.addr, cmd)
-			}
-		}
-		start := len(buf)
-		var replyFunc replyFunc
-		switch op := op.(type) {
-
-		case *updateOp:
-			buf = addHeader(buf, 2001)
-			buf = addInt32(buf, 0) // Reserved
-			buf = addCString(buf, op.Collection)
-			buf = addInt32(buf, int32(op.Flags))
-			debugf("Socket %p to %s: serializing selector document: %#v", socket, socket.addr, op.Selector)
-			buf, err = addBSON(buf, op.Selector)
-			if err != nil {
-				return err
-			}
-			debugf("Socket %p to %s: serializing update document: %#v", socket, socket.addr, op.Update)
-			buf, err = addBSON(buf, op.Update)
-			if err != nil {
-				return err
-			}
-
-		case *insertOp:
-			buf = addHeader(buf, 2002)
-			buf = addInt32(buf, int32(op.flags))
-			buf = addCString(buf, op.collection)
-			for _, doc := range op.documents {
-				debugf("Socket %p to %s: serializing document for insertion: %#v", socket, socket.addr, doc)
-				buf, err = addBSON(buf, doc)
-				if err != nil {
-					return err
-				}
-			}
-
-		case *queryOp:
-			buf = addHeader(buf, 2004)
-			buf = addInt32(buf, int32(op.flags))
-			buf = addCString(buf, op.collection)
-			buf = addInt32(buf, op.skip)
-			buf = addInt32(buf, op.limit)
-			buf, err = addBSON(buf, op.finalQuery(socket))
-			if err != nil {
-				return err
-			}
-			if op.selector != nil {
-				buf, err = addBSON(buf, op.selector)
-				if err != nil {
-					return err
-				}
-			}
-			replyFunc = op.replyFunc
-
-		case *getMoreOp:
-			buf = addHeader(buf, 2005)
-			buf = addInt32(buf, 0) // Reserved
-			buf = addCString(buf, op.collection)
-			buf = addInt32(buf, op.limit)
-			buf = addInt64(buf, op.cursorId)
-			replyFunc = op.replyFunc
-
-		case *deleteOp:
-			buf = addHeader(buf, 2006)
-			buf = addInt32(buf, 0) // Reserved
-			buf = addCString(buf, op.Collection)
-			buf = addInt32(buf, int32(op.Flags))
-			debugf("Socket %p to %s: serializing selector document: %#v", socket, socket.addr, op.Selector)
-			buf, err = addBSON(buf, op.Selector)
-			if err != nil {
-				return err
-			}
-
-		case *killCursorsOp:
-			buf = addHeader(buf, 2007)
-			buf = addInt32(buf, 0) // Reserved
-			buf = addInt32(buf, int32(len(op.cursorIds)))
-			for _, cursorId := range op.cursorIds {
-				buf = addInt64(buf, cursorId)
-			}
-
-		default:
-			panic("internal error: unknown operation type")
-		}
-
-		setInt32(buf, start, int32(len(buf)-start))
-
-		if replyFunc != nil {
-			request := &requests[requestCount]
-			request.replyFunc = replyFunc
-			request.bufferPos = start
-			requestCount++
-		}
-	}
-
-	// Buffer is ready for the pipe.  Lock, allocate ids, and enqueue.
-
-	socket.Lock()
-	if socket.dead != nil {
-		dead := socket.dead
-		socket.Unlock()
-		debugf("Socket %p to %s: failing query, already closed: %s", socket, socket.addr, socket.dead.Error())
-		// XXX This seems necessary in case the session is closed concurrently
-		// with a query being performed, but it's not yet tested:
-		for i := 0; i != requestCount; i++ {
-			request := &requests[i]
-			if request.replyFunc != nil {
-				request.replyFunc(dead, nil, -1, nil)
-			}
-		}
-		return dead
-	}
-
-	wasWaiting := len(socket.replyFuncs) > 0
-
-	// Reserve id 0 for requests which should have no responses.
-	requestId := socket.nextRequestId + 1
-	if requestId == 0 {
-		requestId++
-	}
-	socket.nextRequestId = requestId + uint32(requestCount)
-	for i := 0; i != requestCount; i++ {
-		request := &requests[i]
-		setInt32(buf, request.bufferPos+4, int32(requestId))
-		socket.replyFuncs[requestId] = request.replyFunc
-		requestId++
-	}
-
-	debugf("Socket %p to %s: sending %d op(s) (%d bytes)", socket, socket.addr, len(ops), len(buf))
-	stats.sentOps(len(ops))
-
-	socket.updateDeadline(writeDeadline)
-	_, err = socket.conn.Write(buf)
-	if !wasWaiting && requestCount > 0 {
-		socket.updateDeadline(readDeadline)
-	}
-	socket.Unlock()
-	return err
-}
-
-func fill(r net.Conn, b []byte) error {
-	l := len(b)
-	n, err := r.Read(b)
-	for n != l && err == nil {
-		var ni int
-		ni, err = r.Read(b[n:])
-		n += ni
-	}
-	return err
-}
-
-// Estimated minimum cost per socket: 1 goroutine + memory for the largest
-// document ever seen.
-func (socket *mongoSocket) readLoop() {
-	p := make([]byte, 36) // 16 from header + 20 from OP_REPLY fixed fields
-	s := make([]byte, 4)
-	conn := socket.conn // No locking, conn never changes.
-	for {
-		err := fill(conn, p)
-		if err != nil {
-			socket.kill(err, true)
-			return
-		}
-
-		totalLen := getInt32(p, 0)
-		responseTo := getInt32(p, 8)
-		opCode := getInt32(p, 12)
-
-		// Don't use socket.server.Addr here.  socket is not
-		// locked and socket.server may go away.
-		debugf("Socket %p to %s: got reply (%d bytes)", socket, socket.addr, totalLen)
-
-		_ = totalLen
-
-		if opCode != 1 {
-			socket.kill(errors.New("opcode != 1, corrupted data?"), true)
-			return
-		}
-
-		reply := replyOp{
-			flags:     uint32(getInt32(p, 16)),
-			cursorId:  getInt64(p, 20),
-			firstDoc:  getInt32(p, 28),
-			replyDocs: getInt32(p, 32),
-		}
-
-		stats.receivedOps(+1)
-		stats.receivedDocs(int(reply.replyDocs))
-
-		socket.Lock()
-		replyFunc, ok := socket.replyFuncs[uint32(responseTo)]
-		if ok {
-			delete(socket.replyFuncs, uint32(responseTo))
-		}
-		socket.Unlock()
-
-		if replyFunc != nil && reply.replyDocs == 0 {
-			replyFunc(nil, &reply, -1, nil)
-		} else {
-			for i := 0; i != int(reply.replyDocs); i++ {
-				err := fill(conn, s)
-				if err != nil {
-					if replyFunc != nil {
-						replyFunc(err, nil, -1, nil)
-					}
-					socket.kill(err, true)
-					return
-				}
-
-				b := make([]byte, int(getInt32(s, 0)))
-
-				// copy(b, s) in an efficient way.
-				b[0] = s[0]
-				b[1] = s[1]
-				b[2] = s[2]
-				b[3] = s[3]
-
-				err = fill(conn, b[4:])
-				if err != nil {
-					if replyFunc != nil {
-						replyFunc(err, nil, -1, nil)
-					}
-					socket.kill(err, true)
-					return
-				}
-
-				if globalDebug && globalLogger != nil {
-					m := bson.M{}
-					if err := bson.Unmarshal(b, m); err == nil {
-						debugf("Socket %p to %s: received document: %#v", socket, socket.addr, m)
-					}
-				}
-
-				if replyFunc != nil {
-					replyFunc(nil, &reply, i, b)
-				}
-
-				// XXX Do bound checking against totalLen.
-			}
-		}
-
-		socket.Lock()
-		if len(socket.replyFuncs) == 0 {
-			// Nothing else to read for now. Disable deadline.
-			socket.conn.SetReadDeadline(time.Time{})
-		} else {
-			socket.updateDeadline(readDeadline)
-		}
-		socket.Unlock()
-
-		// XXX Do bound checking against totalLen.
-	}
-}
-
-var emptyHeader = []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
-
-func addHeader(b []byte, opcode int) []byte {
-	i := len(b)
-	b = append(b, emptyHeader...)
-	// Enough for current opcodes.
-	b[i+12] = byte(opcode)
-	b[i+13] = byte(opcode >> 8)
-	return b
-}
-
-func addInt32(b []byte, i int32) []byte {
-	return append(b, byte(i), byte(i>>8), byte(i>>16), byte(i>>24))
-}
-
-func addInt64(b []byte, i int64) []byte {
-	return append(b, byte(i), byte(i>>8), byte(i>>16), byte(i>>24),
-		byte(i>>32), byte(i>>40), byte(i>>48), byte(i>>56))
-}
-
-func addCString(b []byte, s string) []byte {
-	b = append(b, []byte(s)...)
-	b = append(b, 0)
-	return b
-}
-
-func addBSON(b []byte, doc interface{}) ([]byte, error) {
-	if doc == nil {
-		return append(b, 5, 0, 0, 0, 0), nil
-	}
-	data, err := bson.Marshal(doc)
-	if err != nil {
-		return b, err
-	}
-	return append(b, data...), nil
-}
-
-func setInt32(b []byte, pos int, i int32) {
-	b[pos] = byte(i)
-	b[pos+1] = byte(i >> 8)
-	b[pos+2] = byte(i >> 16)
-	b[pos+3] = byte(i >> 24)
-}
-
-func getInt32(b []byte, pos int) int32 {
-	return (int32(b[pos+0])) |
-		(int32(b[pos+1]) << 8) |
-		(int32(b[pos+2]) << 16) |
-		(int32(b[pos+3]) << 24)
-}
-
-func getInt64(b []byte, pos int) int64 {
-	return (int64(b[pos+0])) |
-		(int64(b[pos+1]) << 8) |
-		(int64(b[pos+2]) << 16) |
-		(int64(b[pos+3]) << 24) |
-		(int64(b[pos+4]) << 32) |
-		(int64(b[pos+5]) << 40) |
-		(int64(b[pos+6]) << 48) |
-		(int64(b[pos+7]) << 56)
-}
diff --git a/vendor/gopkg.in/mgo.v2/stats.go b/vendor/gopkg.in/mgo.v2/stats.go
deleted file mode 100644
index 59723e6..0000000
--- a/vendor/gopkg.in/mgo.v2/stats.go
+++ /dev/null
@@ -1,147 +0,0 @@
-// mgo - MongoDB driver for Go
-//
-// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
-//
-// All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are met:
-//
-// 1. Redistributions of source code must retain the above copyright notice, this
-//    list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright notice,
-//    this list of conditions and the following disclaimer in the documentation
-//    and/or other materials provided with the distribution.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-package mgo
-
-import (
-	"sync"
-)
-
-var stats *Stats
-var statsMutex sync.Mutex
-
-func SetStats(enabled bool) {
-	statsMutex.Lock()
-	if enabled {
-		if stats == nil {
-			stats = &Stats{}
-		}
-	} else {
-		stats = nil
-	}
-	statsMutex.Unlock()
-}
-
-func GetStats() (snapshot Stats) {
-	statsMutex.Lock()
-	snapshot = *stats
-	statsMutex.Unlock()
-	return
-}
-
-func ResetStats() {
-	statsMutex.Lock()
-	debug("Resetting stats")
-	old := stats
-	stats = &Stats{}
-	// These are absolute values:
-	stats.Clusters = old.Clusters
-	stats.SocketsInUse = old.SocketsInUse
-	stats.SocketsAlive = old.SocketsAlive
-	stats.SocketRefs = old.SocketRefs
-	statsMutex.Unlock()
-	return
-}
-
-type Stats struct {
-	Clusters     int
-	MasterConns  int
-	SlaveConns   int
-	SentOps      int
-	ReceivedOps  int
-	ReceivedDocs int
-	SocketsAlive int
-	SocketsInUse int
-	SocketRefs   int
-}
-
-func (stats *Stats) cluster(delta int) {
-	if stats != nil {
-		statsMutex.Lock()
-		stats.Clusters += delta
-		statsMutex.Unlock()
-	}
-}
-
-func (stats *Stats) conn(delta int, master bool) {
-	if stats != nil {
-		statsMutex.Lock()
-		if master {
-			stats.MasterConns += delta
-		} else {
-			stats.SlaveConns += delta
-		}
-		statsMutex.Unlock()
-	}
-}
-
-func (stats *Stats) sentOps(delta int) {
-	if stats != nil {
-		statsMutex.Lock()
-		stats.SentOps += delta
-		statsMutex.Unlock()
-	}
-}
-
-func (stats *Stats) receivedOps(delta int) {
-	if stats != nil {
-		statsMutex.Lock()
-		stats.ReceivedOps += delta
-		statsMutex.Unlock()
-	}
-}
-
-func (stats *Stats) receivedDocs(delta int) {
-	if stats != nil {
-		statsMutex.Lock()
-		stats.ReceivedDocs += delta
-		statsMutex.Unlock()
-	}
-}
-
-func (stats *Stats) socketsInUse(delta int) {
-	if stats != nil {
-		statsMutex.Lock()
-		stats.SocketsInUse += delta
-		statsMutex.Unlock()
-	}
-}
-
-func (stats *Stats) socketsAlive(delta int) {
-	if stats != nil {
-		statsMutex.Lock()
-		stats.SocketsAlive += delta
-		statsMutex.Unlock()
-	}
-}
-
-func (stats *Stats) socketRefs(delta int) {
-	if stats != nil {
-		statsMutex.Lock()
-		stats.SocketRefs += delta
-		statsMutex.Unlock()
-	}
-}
diff --git a/vendor/vendor.json b/vendor/vendor.json
index d7c72ad..c17ad30 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -909,36 +909,6 @@
 			"revisionTime": "2016-12-22T00:19:25Z"
 		},
 		{
-			"checksumSHA1": "1D8GzeoFGUs5FZOoyC2DpQg8c5Y=",
-			"path": "gopkg.in/mgo.v2",
-			"revision": "3f83fa5005286a7fe593b055f0d7771a7dce4655",
-			"revisionTime": "2016-08-18T02:01:20Z"
-		},
-		{
-			"checksumSHA1": "YsB2DChSV9HxdzHaKATllAUKWSI=",
-			"path": "gopkg.in/mgo.v2/bson",
-			"revision": "3f83fa5005286a7fe593b055f0d7771a7dce4655",
-			"revisionTime": "2016-08-18T02:01:20Z"
-		},
-		{
-			"checksumSHA1": "XQsrqoNT1U0KzLxOFcAZVvqhLfk=",
-			"path": "gopkg.in/mgo.v2/internal/json",
-			"revision": "3f83fa5005286a7fe593b055f0d7771a7dce4655",
-			"revisionTime": "2016-08-18T02:01:20Z"
-		},
-		{
-			"checksumSHA1": "LEvMCnprte47qdAxWvQ/zRxVF1U=",
-			"path": "gopkg.in/mgo.v2/internal/sasl",
-			"revision": "3f83fa5005286a7fe593b055f0d7771a7dce4655",
-			"revisionTime": "2016-08-18T02:01:20Z"
-		},
-		{
-			"checksumSHA1": "+1WDRPaOphSCmRMxVPIPBV4aubc=",
-			"path": "gopkg.in/mgo.v2/internal/scram",
-			"revision": "3f83fa5005286a7fe593b055f0d7771a7dce4655",
-			"revisionTime": "2016-08-18T02:01:20Z"
-		},
-		{
 			"checksumSHA1": "12GqsW8PiRPnezDDy0v4brZrndM=",
 			"path": "gopkg.in/yaml.v2",
 			"revision": "a5b47d31c556af34a302ce5d659e6fea44d90de0",