Simplify license variations, and add missing license texts.

Simplify license variations, and add missing license texts.

* ChangeLog, ChangeLog.1996, ChangeLog.1997, ChangeLog.1998,
ChangeLog.1999, ChangeLog.2000, ChangeLog.2001, ChangeLog.2002,
ChangeLog.2003, ChangeLog.2004, ChangeLog.2005, ChangeLog.2006,
ChangeLog.2007, ChangeLog.2008, ChangeLog.2009, NEWS: Add
all-permissive license.
* HACKING, README, README.alpha, TODO: Relax license to RMS
encouraged all-permissive terms.
* libltdl/README: Ditto. I added the original license text in
2007, and there's no need for it to be so long for such a trivial
file.
* libltdl/config/getopt.m4sh, libltdl/general.m4sh: Cvs-utils is
dead, and I am the author of these files, so consolidated license
terms to match regular Libtool licensing.
* HACKING (Licensing Rules): Update wording, and list of files for
the all permissive license.
(GPL with CVS-Utils exception clause): Removed.  No files have these
license any more.
(GPL with Libtool exception clause): Ditto, only libltdl/README
used to be distributed with this variation.
* AUTHORS: Add GPL license text.