2003-05-14  Michael Natterer  <mitch@gimp.org>

	* app/core/Makefile.am
	* app/core/gimp-utils.[ch]: new file for utility functions.
	Contains gimp_rectangle_intersect() for now.

	* app/core/gimpdrawable-transform.c: removed the function here.

	* app/core/gimpdrawable.c (gimp_drawable_resize): use it to
	determine the amount of pixels to copy between the old and new
	tile managers. Removed restriction that forced the areas to
	overlap by at least one pixel.

	* app/core/gimpitem.c (gimp_item_real_transform): removed the
	restriction here, too.

	* app/core/gimplayer.c (gimp_layer_create_mask): use the new
	function to decide how much to copy from the selection when
	creating a mask from it.