1999-06-20  Michael Natterer  <mitschel@cs.tu-berlin.de>

	* app/commands.c
	* app/disp_callbacks.c
	* app/gdisplay.c
	* app/lc_dialog.c
	* app/menus.c: applied a patch from <Simon.Budig@unix-ag.org>
	which implements tear-off-menus(!!!). Modified it to use the
	GimpContext.
	The sensitivity of the menu entries is not updated after
	executing a command. This leaves the sensitivity in the state
	before the command was executed (which is buggy). Will probably
	have to update the sensitivity from gdisplays_flush().
	Simon called the patch "temporary" but it looks pretty stable to
	me. Please test it :-)

	* app/context_manager.[ch]: minor changes.

	* app/gimpcontext.[ch]: the user context keeps track of the
	current display and image. The image is set automatically from
	gimp_context_set_display().
	Still have to figure out how this should interact with
	gdisplay_active() (the current state is a hack).
	Made the context attributes real GtkObject arguments.
	Pass the changed attributes to the callbacks which connect to
	the <attribute>_changed signals.

	* app/gimpset.[ch]
	* app/gimpsetF.h
	* app/gimpsetP.h: made the gimpset properly derivable by adding
	signal slots to the object class structure. Added copyright
	headers.

	* app/gimpsignal.[ch]: new type gimp_sigtype_double, copyright
	header and my usual indentation fanaticism.