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, 212 insertions, 0 deletions

diff --git a/lib/llist.c b/lib/llist.c
new file mode 100644
index 000000000..a302e32d5
--- /dev/null
+++ b/lib/llist.c
@@ -0,0 +1,212 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  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 "setup.h"
+
+#include "llist.h"
+#include "curl_memory.h"
+
+/* this must be the last include file */
+#include "memdebug.h"
+
+/*
+ * @unittest: 1300
+ */
+static void
+llist_init(struct curl_llist *l, curl_llist_dtor dtor)
+{
+  l->size = 0;
+  l->dtor = dtor;
+  l->head = NULL;
+  l->tail = NULL;
+}
+
+struct curl_llist *
+Curl_llist_alloc(curl_llist_dtor dtor)
+{
+  struct curl_llist *list;
+
+  list = malloc(sizeof(struct curl_llist));
+  if(!list)
+    return NULL;
+
+  llist_init(list, dtor);
+
+  return list;
+}
+
+/*
+ * Curl_llist_insert_next()
+ *
+ * Inserts a new list element after the given one 'e'. If the given existing
+ * entry is NULL and the list already has elements, the new one will be
+ * inserted first in the list.
+ *
+ * Returns: 1 on success and 0 on failure.
+ *
+ * @unittest: 1300
+ */
+int
+Curl_llist_insert_next(struct curl_llist *list, struct curl_llist_element *e,
+                       const void *p)
+{
+  struct curl_llist_element *ne = malloc(sizeof(struct curl_llist_element));
+  if(!ne)
+    return 0;
+
+  ne->ptr = (void *) p;
+  if(list->size == 0) {
+    list->head = ne;
+    list->head->prev = NULL;
+    list->head->next = NULL;
+    list->tail = ne;
+  }
+  else {
+    /* if 'e' is NULL here, we insert the new element first in the list */
+    ne->next = e?e->next:list->head;
+    ne->prev = e;
+    if(!e) {
+      list->head->prev = ne;
+      list->head = ne;
+    }
+    else if(e->next) {
+      e->next->prev = ne;
+    }
+    else {
+      list->tail = ne;
+    }
+    if(e)
+      e->next = ne;
+  }
+
+  ++list->size;
+
+  return 1;
+}
+
+/*
+ * @unittest: 1300
+ */
+int
+Curl_llist_remove(struct curl_llist *list, struct curl_llist_element *e,
+                  void *user)
+{
+  if(e == NULL || list->size == 0)
+    return 1;
+
+  if(e == list->head) {
+    list->head = e->next;
+
+    if(list->head == NULL)
+      list->tail = NULL;
+    else
+      e->next->prev = NULL;
+  }
+  else {
+    e->prev->next = e->next;
+    if(!e->next)
+      list->tail = e->prev;
+    else
+      e->next->prev = e->prev;
+  }
+
+  list->dtor(user, e->ptr);
+
+  e->ptr  = NULL;
+  e->prev = NULL;
+  e->next = NULL;
+
+  free(e);
+  --list->size;
+
+  return 1;
+}
+
+void
+Curl_llist_destroy(struct curl_llist *list, void *user)
+{
+  if(list) {
+    while(list->size > 0)
+      Curl_llist_remove(list, list->tail, user);
+
+    free(list);
+  }
+}
+
+size_t
+Curl_llist_count(struct curl_llist *list)
+{
+  return list->size;
+}
+
+/*
+ * @unittest: 1300
+ */
+int Curl_llist_move(struct curl_llist *list, struct curl_llist_element *e,
+                    struct curl_llist *to_list,
+                    struct curl_llist_element *to_e)
+{
+  /* Remove element from list */
+  if(e == NULL || list->size == 0)
+    return 0;
+
+  if(e == list->head) {
+    list->head = e->next;
+
+    if(list->head == NULL)
+      list->tail = NULL;
+    else
+      e->next->prev = NULL;
+  }
+  else {
+    e->prev->next = e->next;
+    if(!e->next)
+      list->tail = e->prev;
+    else
+      e->next->prev = e->prev;
+  }
+
+  --list->size;
+
+  /* Add element to to_list after to_e */
+  if(to_list->size == 0) {
+    to_list->head = e;
+    to_list->head->prev = NULL;
+    to_list->head->next = NULL;
+    to_list->tail = e;
+  }
+  else {
+    e->next = to_e->next;
+    e->prev = to_e;
+    if(to_e->next) {
+      to_e->next->prev = e;
+    }
+    else {
+      to_list->tail = e;
+    }
+    to_e->next = e;
+  }
+
+  ++to_list->size;
+
+  return 1;
+}