2001-02-21  Michael Natterer  <mitch@gimp.org>

	Made the tool system work again and integrated it back with the
	GimpContext. It's a hack between old, new and freshly hacked
	stuff. There are still lots of warnings but at least we can switch
	tools again.

	* app/tools/Makefile.am
	* app/tools/gimptoolinfo.[ch]: resurrected as real object.
	The GimpToolInfo objects are derived from GimpData, which gives
	us the tool icon stuff for free. Also, we need a list of _objects_
	which is allocated all the time. All tools are required to have
	a "register" function which registers themselves with the list
	of GimpToolInfo objects which is maintained by the tool manager.

	* app/tools/tool.[ch]: made a real GtkObject with properly named
	functions out of it. The former "active_tool_control" is of
	course not the default implementation of the tool's "control"
	method but a hack _around_ it, so it went to the tool manager.

	* app/tools/color_picker.[ch]
	* app/tools/measure.[ch]: ditto. Added "register" functions and
	"destroy" implementations so the tools go away after use.

	* app/tools/tool_manager.[ch]: badly hacked at the moment to keep
	both the list of class structures _and_ the tool info list.

	* app/tools/tools.c: call the tools' register functions.

	* app/gimpcontext.[ch]: store a pointer to a GimpToolInfo object
	as "active_tool" in the context, so we're independent of tools
	being allocated or not. It's treated just like a brush or pattern
	now.

	* app/gimpdnd.[ch]: made tool DND work like all other DND types.

	* app/devices.[ch]: also here: the tool is just a normal data object
	now, resulting in removal of lots of code.

	* app/commands.c
	* app/context_manager.c: updated the tool select and context stuff
	to work again.

	* app/toolbox.c: removed the old pixmap buttons and put GimpPreviews
	inside the tool buttons. Still needs an own preview type to
	look nice.

	* app/disp_callbacks.c
	* app/about_dialog.c
	* app/app_procs.c
	* app/appenums.h
	* app/apptypes.h
	* app/gimage.c
	* app/gimppalette.c
	* app/gimppreview.c
	* app/gimprc.c
	* app/info_window.c
	* app/menus.c
	* app/palette_select.h
	* app/scale.c
	* app/scroll.c: lots of changes to make it work again.