Revert changes relative to lib/*.[ch] recent renaming

This reverts renaming and usage of lib/*.h header files done
28-12-2012, reverting 2 commits:

  f871de0... build: make use of 76 lib/*.h renamed files
  ffd8e12... build: rename 76 lib/*.h files

This also reverts removal of redundant include guard (redundant thanks
to changes in above commits) done 2-12-2013, reverting 1 commit:

  c087374... curl_setup.h: remove redundant include guard

This also reverts renaming and usage of lib/*.c source files done
3-12-2013, reverting 3 commits:

  13606bb... build: make use of 93 lib/*.c renamed files
  5b6e792... build: rename 93 lib/*.c files
  7d83dff... build: commit 13606bbfde follow-up 1

Start of related discussion thread:

  http://curl.haxx.se/mail/lib-2013-01/0012.html

Asking for confirmation on pushing this revertion commit:

  http://curl.haxx.se/mail/lib-2013-01/0048.html

Confirmation summary:

  http://curl.haxx.se/mail/lib-2013-01/0079.html

NOTICE: The list of 2 files that have been modified by other
intermixed commits, while renamed, and also by at least one
of the 6 commits this one reverts follows below. These 2 files
will exhibit a hole in history unless git's '--follow' option
is used when viewing logs.

  lib/curl_imap.h
  lib/curl_smtp.h

1 files changed, 0 insertions, 84 deletions

diff --git a/lib/curl_pop3.h b/lib/curl_pop3.h
deleted file mode 100644
index 62b88fdac..000000000
--- a/lib/curl_pop3.h
+++ /dev/null
@@ -1,84 +0,0 @@
-#ifndef HEADER_CURL_POP3_H
-#define HEADER_CURL_POP3_H
-/***************************************************************************
- *                                  _   _ ____  _
- *  Project                     ___| | | |  _ \| |
- *                             / __| | | | |_) | |
- *                            | (__| |_| |  _ <| |___
- *                             \___|\___/|_| \_\_____|
- *
- * Copyright (C) 2009 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
- *
- * This software is licensed as described in the file COPYING, which
- * you should have received as part of this distribution. The terms
- * are also available at http://curl.haxx.se/docs/copyright.html.
- *
- * You may opt to use, copy, modify, merge, publish, distribute and/or sell
- * copies of the Software, and permit persons to whom the Software is
- * furnished to do so, under the terms of the COPYING file.
- *
- * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
- * KIND, either express or implied.
- *
- ***************************************************************************/
-
-/****************************************************************************
- * POP3 unique setup
- ***************************************************************************/
-typedef enum {
-  POP3_STOP,         /* do nothing state, stops the state machine */
-  POP3_SERVERGREET,  /* waiting for the initial greeting immediately after
-                        a connect */
-  POP3_STARTTLS,
-  POP3_CAPA,
-  POP3_AUTH_PLAIN,
-  POP3_AUTH_LOGIN,
-  POP3_AUTH_LOGIN_PASSWD,
-  POP3_AUTH_CRAMMD5,
-  POP3_AUTH_DIGESTMD5,
-  POP3_AUTH_DIGESTMD5_RESP,
-  POP3_AUTH_NTLM,
-  POP3_AUTH_NTLM_TYPE2MSG,
-  POP3_AUTH,
-  POP3_APOP,
-  POP3_USER,
-  POP3_PASS,
-  POP3_COMMAND,
-  POP3_QUIT,
-  POP3_LAST          /* never used */
-} pop3state;
-
-/* pop3_conn is used for struct connection-oriented data in the connectdata
-   struct */
-struct pop3_conn {
-  struct pingpong pp;
-  char *mailbox;          /* Message ID */
-  char *custom;           /* Custom Request */
-  size_t eob;             /* Number of bytes of the EOB (End Of Body) that
-                             have been received so far */
-  size_t strip;           /* Number of bytes from the start to ignore as
-                             non-body */
-  unsigned int authtypes; /* Supported authentication types */
-  unsigned int authmechs; /* Accepted SASL authentication mechanisms */
-  unsigned int authused;  /* SASL auth mechanism used for the connection */
-  char *apoptimestamp;    /* APOP timestamp from the server greeting */
-  pop3state state;        /* Always use curl_pop3.c:state() to change state */
-};
-
-extern const struct Curl_handler Curl_handler_pop3;
-extern const struct Curl_handler Curl_handler_pop3s;
-
-/* Authentication type flags */
-#define POP3_TYPE_CLEARTEXT 0x0001
-#define POP3_TYPE_APOP      0x0002
-#define POP3_TYPE_SASL      0x0004
-
-/* This is the 5-bytes End-Of-Body marker for POP3 */
-#define POP3_EOB "\x0d\x0a\x2e\x0d\x0a"
-#define POP3_EOB_LEN 5
-
-/* This function scans the body after the end-of-body and writes everything
- * until the end is found */
-CURLcode Curl_pop3_write(struct connectdata *conn, char *str, size_t nread);
-
-#endif /* HEADER_CURL_POP3_H */