2004-09-03  Sven Neumann  <sven@gimp.org>

	* libgimpbase/Makefile.am
	* libgimpbase/gimpchecks.[ch] added gimp_checks_get_shades().

	* app/base/temp-buf.c
	* app/display/gimpdisplayshell-render.c
	* libgimpwidgets/gimppreviewarea.c: use the new function instead
	of replicating these numbers in three different places.