There are really too many changes to mention them all here, previous version
of the package was 20 htmldoc versions behind! See the file CHANGES.txt in the
sources for more details. Anyway you should update.
As suggested in PR pkg/14557 by <collver@linuxfreemail.com> the package had
been strongly buildlinked. This update address part of this PR.
Also introduce support for another package of htmldoc with the X Windows GUI
activated.
