2006-11-02  Michael Natterer  <mitch@gimp.org>

	Don't let each terminating plug-in procedure end its progress,
	because that progress may still be in use by another plug-in.

	* app/plug-in/gimpplugin-progress.[ch]
	(gimp_plug_in_progress_attach)
	(gimp_plug_in_progress_detach): new functions which maintain
	a simple attach count for a GimpProgress

	* app/plug-in/gimpplugin-progress.c
	* app/plug-in/gimppluginprocframe.c: call attach() when setting
	proc_frame->progress. Call detach() in gimp_plug_in_progress_end()
	and only call gimp_progress_end() if detaching lowered the attach
	count to 0.