Manually tweak Doxyfile to squash warnings.

Manually tweak Doxyfile to squash warnings.

The Doxyfile introduced by the previous commit (created by running doxygen -u)
causes doxygen to complain:

	warning: Tag 'TCL_SUBST' at line 260 of file '-' has become obsolete.
		 To avoid this warning please remove this line from your configuration file or upgrade it using "doxygen -u"
	warning: argument 'a4wide' for option PAPER_TYPE is not a valid enum value
	Using the default: a4!

This patch should get rid of the warnings.