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, 127 deletions

diff --git a/lib/curl_slist.c b/lib/curl_slist.c
deleted file mode 100644
index 2a30ea620..000000000
--- a/lib/curl_slist.c
+++ /dev/null
@@ -1,127 +0,0 @@
-/***************************************************************************
- *                                  _   _ ____  _
- *  Project                     ___| | | |  _ \| |
- *                             / __| | | | |_) | |
- *                            | (__| |_| |  _ <| |___
- *                             \___|\___/|_| \_\_____|
- *
- * Copyright (C) 1998 - 2011, 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.
- *
- ***************************************************************************/
-
-#include "curl_setup.h"
-
-#include "curl_memory.h"
-#include "curl_slist.h"
-
-/* The last #include file should be: */
-#include "curl_memdebug.h"
-
-/* returns last node in linked list */
-static struct curl_slist *slist_get_last(struct curl_slist *list)
-{
-  struct curl_slist     *item;
-
-  /* if caller passed us a NULL, return now */
-  if(!list)
-    return NULL;
-
-  /* loop through to find the last item */
-  item = list;
-  while(item->next) {
-    item = item->next;
-  }
-  return item;
-}
-
-/*
- * curl_slist_append() appends a string to the linked list. It always returns
- * the address of the first record, so that you can use this function as an
- * initialization function as well as an append function. If you find this
- * bothersome, then simply create a separate _init function and call it
- * appropriately from within the program.
- */
-struct curl_slist *curl_slist_append(struct curl_slist *list,
-                                     const char *data)
-{
-  struct curl_slist     *last;
-  struct curl_slist     *new_item;
-
-  new_item = malloc(sizeof(struct curl_slist));
-  if(new_item) {
-    char *dupdata = strdup(data);
-    if(dupdata) {
-      new_item->next = NULL;
-      new_item->data = dupdata;
-    }
-    else {
-      free(new_item);
-      return NULL;
-    }
-  }
-  else
-    return NULL;
-
-  if(list) {
-    last = slist_get_last(list);
-    last->next = new_item;
-    return list;
-  }
-
-  /* if this is the first item, then new_item *is* the list */
-  return new_item;
-}
-
-/*
- * Curl_slist_duplicate() duplicates a linked list. It always returns the
- * address of the first record of the cloned list or NULL in case of an
- * error (or if the input list was NULL).
- */
-struct curl_slist *Curl_slist_duplicate(struct curl_slist *inlist)
-{
-  struct curl_slist *outlist = NULL;
-  struct curl_slist *tmp;
-
-  while(inlist) {
-    tmp = curl_slist_append(outlist, inlist->data);
-
-    if(!tmp) {
-      curl_slist_free_all(outlist);
-      return NULL;
-    }
-
-    outlist = tmp;
-    inlist = inlist->next;
-  }
-  return outlist;
-}
-
-/* be nice and clean up resources */
-void curl_slist_free_all(struct curl_slist *list)
-{
-  struct curl_slist     *next;
-  struct curl_slist     *item;
-
-  if(!list)
-    return;
-
-  item = list;
-  do {
-    next = item->next;
-    Curl_safefree(item->data);
-    free(item);
-    item = next;
-  } while(next);
-}
-