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, 68 insertions, 0 deletions

diff --git a/lib/strtoofft.h b/lib/strtoofft.h
new file mode 100644
index 000000000..08b0e6d91
--- /dev/null
+++ b/lib/strtoofft.h
@@ -0,0 +1,68 @@
+#ifndef HEADER_CURL_STRTOOFFT_H
+#define HEADER_CURL_STRTOOFFT_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2010, 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"
+
+/*
+ * Determine which string to integral data type conversion function we use
+ * to implement string conversion to our curl_off_t integral data type.
+ *
+ * Notice that curl_off_t might be 64 or 32 bit wide, and that it might use
+ * an underlying data type which might be 'long', 'int64_t', 'long long' or
+ * '__int64' and more remotely other data types.
+ *
+ * On systems where the size of curl_off_t is greater than the size of 'long'
+ * the conversion function to use is strtoll() if it is available, otherwise,
+ * we emulate its functionality with our own clone.
+ *
+ * On systems where the size of curl_off_t is smaller or equal than the size
+ * of 'long' the conversion function to use is strtol().
+ */
+
+#if (CURL_SIZEOF_CURL_OFF_T > CURL_SIZEOF_LONG)
+#  ifdef HAVE_STRTOLL
+#    define curlx_strtoofft strtoll
+#  else
+#    if defined(_MSC_VER) && (_MSC_VER >= 1300) && (_INTEGRAL_MAX_BITS >= 64)
+       _CRTIMP __int64 __cdecl _strtoi64(const char *, char **, int);
+#      define curlx_strtoofft _strtoi64
+#    else
+       curl_off_t curlx_strtoll(const char *nptr, char **endptr, int base);
+#      define curlx_strtoofft curlx_strtoll
+#      define NEED_CURL_STRTOLL 1
+#    endif
+#  endif
+#else
+#  define curlx_strtoofft strtol
+#endif
+
+#if (CURL_SIZEOF_CURL_OFF_T == 4)
+#  define CURL_OFF_T_MAX CURL_OFF_T_C(0x7FFFFFFF)
+#else
+   /* assume CURL_SIZEOF_CURL_OFF_T == 8 */
+#  define CURL_OFF_T_MAX CURL_OFF_T_C(0x7FFFFFFFFFFFFFFF)
+#endif
+#define CURL_OFF_T_MIN (-CURL_OFF_T_MAX - CURL_OFF_T_C(1))
+
+#endif /* HEADER_CURL_STRTOOFFT_H */