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

lib/hostasyn.c

@@ -0,0 +1,157 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2012, 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"
+
+#ifdef HAVE_NETINET_IN_H
+#include <netinet/in.h>
+#endif
+#ifdef HAVE_NETDB_H
+#include <netdb.h>
+#endif
+#ifdef HAVE_ARPA_INET_H
+#include <arpa/inet.h>
+#endif
+#ifdef __VMS
+#include <in.h>
+#include <inet.h>
+#endif
+
+#ifdef HAVE_PROCESS_H
+#include <process.h>
+#endif
+
+#include "urldata.h"
+#include "sendf.h"
+#include "hostip.h"
+#include "hash.h"
+#include "share.h"
+#include "strerror.h"
+#include "url.h"
+
+#define _MPRINTF_REPLACE /* use our functions only */
+#include <curl/mprintf.h>
+
+#include "curl_memory.h"
+/* The last #include file should be: */
+#include "memdebug.h"
+
+/***********************************************************************
+ * Only for builds using asynchronous name resolves
+ **********************************************************************/
+#ifdef CURLRES_ASYNCH
+
+/*
+ * Curl_addrinfo_callback() gets called by ares, gethostbyname_thread()
+ * or getaddrinfo_thread() when we got the name resolved (or not!).
+ *
+ * If the status argument is CURL_ASYNC_SUCCESS, this function takes
+ * ownership of the Curl_addrinfo passed, storing the resolved data
+ * in the DNS cache.
+ *
+ * The storage operation locks and unlocks the DNS cache.
+ */
+CURLcode Curl_addrinfo_callback(struct connectdata *conn,
+                                int status,
+                                struct Curl_addrinfo *ai)
+{
+  struct Curl_dns_entry *dns = NULL;
+  CURLcode rc = CURLE_OK;
+
+  conn->async.status = status;
+
+  if(CURL_ASYNC_SUCCESS == status) {
+    if(ai) {
+      struct SessionHandle *data = conn->data;
+
+      if(data->share)
+        Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
+
+      dns = Curl_cache_addr(data, ai,
+                            conn->async.hostname,
+                            conn->async.port);
+      if(!dns) {
+        /* failed to store, cleanup and return error */
+        Curl_freeaddrinfo(ai);
+        rc = CURLE_OUT_OF_MEMORY;
+      }
+
+      if(data->share)
+        Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
+    }
+    else {
+      rc = CURLE_OUT_OF_MEMORY;
+    }
+  }
+
+  conn->async.dns = dns;
+
+ /* Set async.done TRUE last in this function since it may be used multi-
+    threaded and once this is TRUE the other thread may read fields from the
+    async struct */
+  conn->async.done = TRUE;
+
+  /* ipv4: The input hostent struct will be freed by ares when we return from
+     this function */
+  return rc;
+}
+
+/* Call this function after Curl_connect() has returned async=TRUE and
+   then a successful name resolve has been received.
+
+   Note: this function disconnects and frees the conn data in case of
+   resolve failure */
+CURLcode Curl_async_resolved(struct connectdata *conn,
+                             bool *protocol_done)
+{
+  CURLcode code;
+
+  if(conn->async.dns) {
+    conn->dns_entry = conn->async.dns;
+    conn->async.dns = NULL;
+  }
+
+  code = Curl_setup_conn(conn, protocol_done);
+
+  if(code)
+    /* We're not allowed to return failure with memory left allocated
+       in the connectdata struct, free those here */
+    Curl_disconnect(conn, FALSE); /* close the connection */
+
+  return code;
+}
+
+/*
+ * Curl_getaddrinfo() is the generic low-level name resolve API within this
+ * source file. There are several versions of this function - for different
+ * name resolve layers (selected at build-time). They all take this same set
+ * of arguments
+ */
+Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
+                                const char *hostname,
+                                int port,
+                                int *waitp)
+{
+  return Curl_resolver_getaddrinfo(conn, hostname, port, waitp);
+}
+
+#endif /* CURLRES_ASYNCH */