2003-12-09  Michael Natterer  <mitch@gimp.org>

	* app/base/tile-manager.c (tile_manager_get_memsize): return a
	more exact result.

	* app/core/gimpimage-scale.[ch] (gimp_image_scale_check): estimate
	the new memsize by separating parts of the image that are constant
	from parts that will scale. Also take undo logic into account.
	Return the estimated new memsize since it's not trivial to
	calculate.

	* app/gui/image-commands.c (image_scale_callback): use the memsize
	returned by gimp_image_scale_check() for the warning message. Free
	allocated strings.