2003-01-29  Michael Natterer  <mitch@gimp.org>

	Fixed bug #97449:

	* app/core/gimpchannel.c (gimp_channel_scale,resize)
	* app/core/gimplayer.c (gimp_layer_scale,resize)
	* app/undo.c (undo_pop_layer_mod,channel_mod): emit "size_changed"
	whenever the size has changed. Cleaned up the two undo_pop
	functions.

	* app/core/gimpimage.c (gimp_image_size_changed): emit
	"size_changed" on all layers/channels so their previews are
	updated correctly on image resize and image resize undo. Don't
	invalidate layers/channels previews here because it's the
	layers'/channels' job to invalidate themselves if needed.