Log Message:
Restructure the following packages:

	www/htmldoc
	www/htmldoc-x11

The latter is now just www/htmldoc built with a specific set of options.
Changes include:

+ Add options.mk that supports a new option:

	htmldoc-gui		Build with GUI support

+ Remove Makefile.common and move all logic into htmldoc/Makefile and
  htmldoc/options.mk.

+ Add full DESTDIR support.

+ Bump the PKGREVISION for htmldoc and htmldoc-x11 to 7.  Both packages
  now track and use the same PKGREVISION number.