muse-latex2png: handle publishing to styles other than HTML

muse-latex2png: handle publishing to styles other than HTML

2006-12-23  Michael Olson  <mwolson@gnu.org>

	* lisp/muse-latex2png.el: Update header, since this has been
	rewritten sufficiently to not need an assignment from the original
	author.
	(muse-latex2png-use-xhtml): Remove, since we now autodetect this.
	(muse-latex2png): Use two underscores to separate prefix and hash.
	(muse-latex2png-region): New function split from
	muse-publish-latex-tag that can be used easily by other code.
	Detect whether we are using an HTML-based publishing style, and
	insert a simpler markup if we are not.  If we are using a
	Latex-based publishing style, do not generate an image, and leave
	the region alone.  Return the path of the generated image, in case
	other functions want to use this programmatically.
	(muse-publish-latex-tag): Set a default prefix based on the name
	of the current file.
	(muse-publish-math-tag): New tag that surrounds the region with
	"$" characters, so that it becomes a Latex math region, and then
	publishes it.

	* lisp/muse-publish.el (muse-style-derived-p): New function that
	returns non-nil if a given style, or the current style if omitted,
	is equal to or derived from the given base style.  This is useful
	in <lisp> tags, because it allows the user to specify markup that
	is only to be inserted for one particular style.
git-archimport-id: mwolson@gnu.org--2006/muse--main--1.0--patch-261