[Groff] GPL or FDL

[Bernd Warken]

The groff source tree is usually licensed to GPL.  That is excellent.

But there are also some documents under the GNU FDL.  This is regarded
as bad by Debian.  Many years ago, Debian made the groff package as
non-free because of the FDL.  So I changed many documentation files in
the groff tree to GPL.

In 2006, Debian made a voting wether the FDL should become free
software:
http://www.debian.org/vote/2006/vote_001.en.html

They decided that the FDL without invariant sections would be compatible
with Debian.  But the Debian discussion about the FDL is right.  There
are still many weaknesses in the FDL.

So which license should we prefer for documentation files:
- make all documentation files into GPL
- make all documentation files into FDL
- keep the licenses of all files as they are

In any case, the file LICENSES has to be updated accordingly.

Bernd Warken