2001-01-29  Michael Natterer  <mitch@gimp.org>

	* app/Makefile.am
	* app/gimpdrawablepreview.[ch]: new file with one set of functions...

	* app/channel.[ch]
	* app/layer.[ch]: ...instead of having everything duplicated three
	times here.

	* app/channels_dialog.c
	* app/floating_sel.c
	* app/floating_sel.h
	* app/gimpdnd.c
	* app/gimpimage.c
	* app/layer_select.c
	* app/layers_dialog.c
	* app/selection.c
	* app/pdb/drawable_cmds.c
	* tools/pdbgen/pdb/drawable.pdb: changed accordingly, cleanup.