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/Makefile.am

@@ -5,7 +5,7 @@
 #                            | (__| |_| |  _ <| |___
 #                             \___|\___/|_| \_\_____|
 #
-# Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
+# 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
@@ -30,47 +30,16 @@ DOCS = README.encoding README.memoryleak README.ares README.curlx	\
 
 CMAKE_DIST = CMakeLists.txt curl_config.h.cmake
 
-EXTRA_DIST = \
- $(CMAKE_DIST) \
- $(DOCS) \
- $(DSP) \
- $(VCPROJ) \
- Makefile.Watcom \
- Makefile.b32 \
- Makefile.m32 \
- Makefile.netware \
- Makefile.vc6 \
- Makefile.vxworks \
- checksrc.pl \
- config-amigaos.h \
- config-dos.h \
- config-mac.h \
- config-os400.h \
- config-riscos.h \
- config-symbian.h \
- config-tpf.h \
- config-vms.h \
- config-vxworks.h \
- config-win32.h \
- config-win32ce.h \
- config-win32ce.h \
- curl_config.h.in \
- curl_nwlib.c \
- curl_nwos.c \
- firefox-db2pem.sh \
- libcurl.plist \
- libcurl.rc \
- makefile.amiga \
- makefile.dj \
- mk-ca-bundle.pl \
- mk-ca-bundle.vbs \
- msvcproj.foot \
- msvcproj.head \
- objnames-test08.sh \
- objnames-test10.sh \
- objnames.inc \
- setup-os400.h \
- vc6libcurl.dsw
+EXTRA_DIST = Makefile.b32 Makefile.m32 Makefile.vc6 $(DSP)              \
+ vc6libcurl.dsw config-win32.h config-win32ce.h config-riscos.h         \
+ config-mac.h curl_config.h.in makefile.dj config-dos.h libcurl.plist   \
+ libcurl.rc config-amigaos.h makefile.amiga                             \
+ Makefile.netware nwlib.c nwos.c msvcproj.head msvcproj.foot		\
+ config-win32ce.h config-os400.h setup-os400.h config-symbian.h		\
+ Makefile.Watcom config-tpf.h $(DOCS) $(VCPROJ) mk-ca-bundle.pl		\
+ mk-ca-bundle.vbs firefox-db2pem.sh $(CMAKE_DIST) config-vxworks.h	\
+ Makefile.vxworks config-vms.h checksrc.pl objnames-test08.sh		\
+ objnames-test10.sh objnames.inc
 
 CLEANFILES = $(DSP) $(VCPROJ)