2003-09-29  Sven Neumann  <sven@gimp.org>

	* app/core/Makefile.am
	* app/core/gimpitem-preview.[ch]: new files with preview code
	factored out of GimpDrawable.

	* app/core/gimpdrawable-preview.[ch]: code removed here.

	* app/core/gimpdrawable.c
	* app/core/gimpitem.c: let GimpItem implement
	GimpViewable::get_preview_size and GimpViewable::get_popup_size.

	* app/widgets/gimppreviewrenderervectors.c: simple scale to the
	renderer's size; it already respects the aspect ratio.