2004-09-01  Sven Neumann  <sven@gimp.org>

	* libgimp/gimpdrawablepreview.[ch]
	* libgimpwidgets/gimppreview.[ch]: always show the "Preview" check
	button. Simplified the preview APIs, moved the "size" style
	property to the GimpPreview class.

	* etc/gtkrc: changed the example accordingly.

	* plug-ins/common/despeckle.c
	* plug-ins/common/gauss.c
	* plug-ins/common/neon.c
	* plug-ins/common/sobel.c
	* plug-ins/common/softglow.c
	* plug-ins/common/spread.c
	* plug-ins/common/unsharp.c: follow change in GimpDrawablePreview API.