Initial implementation of nested tag support

Initial implementation of nested tag support

2006-10-15  Michael Olson  <mwolson@gnu.org>

	* lisp/muse-groff.el (muse-groff-markup-tags): Adapt for nested
	tags.

	* lisp/muse-html.el (muse-html-markup-tags): Ditto.

	* lisp/muse-journal.el (muse-journal-latex-markup-tags): Ditto.

	* lisp/muse-latex2png.el (muse-publish-markup-tags): Ditto.

	* lisp/muse-poem.el (muse-poem-tag): Ditto.

	* lisp/muse-publish.el (muse-publish-markup-tags)
	(muse-publish-markup-header-footer-tags): Shift 4th element to 5th
	element and make 4th element determine whether tags are nestable.
	(muse-publish-goto-tag-end): New function that moves to the end of
	a tag.  Handle nested tags when NESTED is non-nil.
	(muse-publish-markup-tag): Call muse-publish-goto-tag-end.  Use
	5th element for function.
	(muse-publish-quote-tag): Handle nested quote tags.  I've tested
	this on several scenarios, and it seems to work.

	* muse.texi (Markup Tags): Mention nestable tags.
git-archimport-id: mwolson@gnu.org--2006/muse--main--1.0--patch-214