2004-09-22  Michael Natterer  <mitch@gimp.org>

	Prepare for enabling private contexts for plug-ins and scripts:

	* app/plug-in/plug-in.[ch]: removed the "context" member from
	the PlugIn struct and added it to PlugInProcFrame instead.

	* app/plug-in/plug-in-message.c
	* app/plug-in/plug-in-progress.c
	* app/plug-in/plug-in-run.c: changed accordingly.