Backport changes from 1.1.13:
configure.in,doc/GPL.htm,doc/index.htm.in: Remove HTML version of GPL
just link to the FSF's page.
configure.in,doc/Makefile.am,doc/cl2html.pl,doc/index.htm.in: Stop
generating an HTML version of the ChangeLog? - it's too low level to
be of interest to non-developers, and developers can look at the
source code.