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, 134 deletions

diff --git a/lib/curl_timeval.c b/lib/curl_timeval.c
deleted file mode 100644
index 8e4c7bd76..000000000
--- a/lib/curl_timeval.c
+++ /dev/null
@@ -1,134 +0,0 @@
-/***************************************************************************
- *                                  _   _ ____  _
- *  Project                     ___| | | |  _ \| |
- *                             / __| | | | |_) | |
- *                            | (__| |_| |  _ <| |___
- *                             \___|\___/|_| \_\_____|
- *
- * Copyright (C) 1998 - 2008, 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_timeval.h"
-
-#if defined(WIN32) && !defined(MSDOS)
-
-struct timeval curlx_tvnow(void)
-{
-  /*
-  ** GetTickCount() is available on _all_ Windows versions from W95 up
-  ** to nowadays. Returns milliseconds elapsed since last system boot,
-  ** increases monotonically and wraps once 49.7 days have elapsed.
-  */
-  struct timeval now;
-  DWORD milliseconds = GetTickCount();
-  now.tv_sec = milliseconds / 1000;
-  now.tv_usec = (milliseconds % 1000) * 1000;
-  return now;
-}
-
-#elif defined(HAVE_CLOCK_GETTIME_MONOTONIC)
-
-struct timeval curlx_tvnow(void)
-{
-  /*
-  ** clock_gettime() is granted to be increased monotonically when the
-  ** monotonic clock is queried. Time starting point is unspecified, it
-  ** could be the system start-up time, the Epoch, or something else,
-  ** in any case the time starting point does not change once that the
-  ** system has started up.
-  */
-  struct timeval now;
-  struct timespec tsnow;
-  if(0 == clock_gettime(CLOCK_MONOTONIC, &tsnow)) {
-    now.tv_sec = tsnow.tv_sec;
-    now.tv_usec = tsnow.tv_nsec / 1000;
-  }
-  /*
-  ** Even when the configure process has truly detected monotonic clock
-  ** availability, it might happen that it is not actually available at
-  ** run-time. When this occurs simply fallback to other time source.
-  */
-#ifdef HAVE_GETTIMEOFDAY
-  else
-    (void)gettimeofday(&now, NULL);
-#else
-  else {
-    now.tv_sec = (long)time(NULL);
-    now.tv_usec = 0;
-  }
-#endif
-  return now;
-}
-
-#elif defined(HAVE_GETTIMEOFDAY)
-
-struct timeval curlx_tvnow(void)
-{
-  /*
-  ** gettimeofday() is not granted to be increased monotonically, due to
-  ** clock drifting and external source time synchronization it can jump
-  ** forward or backward in time.
-  */
-  struct timeval now;
-  (void)gettimeofday(&now, NULL);
-  return now;
-}
-
-#else
-
-struct timeval curlx_tvnow(void)
-{
-  /*
-  ** time() returns the value of time in seconds since the Epoch.
-  */
-  struct timeval now;
-  now.tv_sec = (long)time(NULL);
-  now.tv_usec = 0;
-  return now;
-}
-
-#endif
-
-/*
- * Make sure that the first argument is the more recent time, as otherwise
- * we'll get a weird negative time-diff back...
- *
- * Returns: the time difference in number of milliseconds.
- */
-long curlx_tvdiff(struct timeval newer, struct timeval older)
-{
-  return (newer.tv_sec-older.tv_sec)*1000+
-    (newer.tv_usec-older.tv_usec)/1000;
-}
-
-/*
- * Same as curlx_tvdiff but with full usec resolution.
- *
- * Returns: the time difference in seconds with subsecond resolution.
- */
-double curlx_tvdiff_secs(struct timeval newer, struct timeval older)
-{
-  if(newer.tv_sec != older.tv_sec)
-    return (double)(newer.tv_sec-older.tv_sec)+
-      (double)(newer.tv_usec-older.tv_usec)/1000000.0;
-  else
-    return (double)(newer.tv_usec-older.tv_usec)/1000000.0;
-}
-
-/* return the number of seconds in the given input timeval struct */
-long Curl_tvlong(struct timeval t1)
-{
-  return t1.tv_sec;
-}