IFS compilation support, SSL GSKit backend by default, TLSv1.[12] support in
  GSKit for OS400 >= V7R1, no more tabs in make scripts.

This reverts renaming and usage of lib/*.h header files done
28-12-2012, reverting 2 commits:

  f871de00... build: make use of 76 lib/*.h renamed files
  ffd8e127... 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:

  c087374c... 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:

  13606bbf... build: make use of 93 lib/*.c renamed files
  5b6e7927... build: rename 93 lib/*.c files
  7d83dfff... build: commit 13606bbf 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

93 *.c source files renamed to use our standard naming scheme.

This change affects 77 files in libcurl's source tree.

Upgrade ILE/RPG binding to 7.21.7.
Update OS400 documentation accordingly.

_ Upgrade OS400 EBCDIC wrappers for new options.
_ Upgrade ILE/RPG bindings to current state.

$capath is known to configure, so it can be defined in config.h instead.

New declarations in curl.h reported to curl.inc.in.
Copyrights extended to 2008.
SONAME handling introduced in build scripts.

Port OS400 compilation scripts to >= V5R2M0