2003-06-19  Michael Natterer  <mitch@gimp.org>

	Changed the semantics of GIMP_EXTENSION and (to some extent)
	of GIMP_PLUGIN:

	The old meaning of EXTENSION was "I live in the toolbox" and
	PLUGIN meant "I take RUN-MODE,IMAGE,DRAWABLE args (but only if I
	am invoked interactively)". This is completely useless, since
	living in the toolbox means having "<Toolbox>" in the menu_path
	and taking RUN-MODE,IMAGE,DRAWABLE means just that, regardless of
	what type of procedure we are.

	The new meaning of GIMP_PLUGIN is just "I am an ordinary procedure,
	I am invoked, do my job and finish", while GIMP_EXTENSION means
	"I will install temporary procedures and I will keep running to
	keep them available".

	(A GIMP_EXTENSION *must* call gimp_extension_ack() now to tell the
	core that it's ready to run, or the core will block waiting for
	the message !!!).

	* configure.in: bumped version number to 1.3.16.

	* libgimpbase/gimpprotocol.h: increased prot...