2002-04-29  Sven Neumann  <sven@gimp.org>

	* app/core/core-enums.[ch]: added new enum GimpThumbnailSize.

	* app/gimprc.c
	* app/config/gimpcoreconfig.[ch]
	* app/core/gimpcoreconfig.[ch]: replaced old gimprc value
	write_thumbnails with thumbnail_size.

	* app/core/gimpimagefile.[ch]: allow to specify a thumbnail size.

	* app/core/gimpdocuments.c
	* app/file/file-open.c
	* app/file/file-save.c
	* app/gui/preferences-dialog.c
	* app/widgets/gimpdocumentview.c: changed accordingly.

	* app/gui/file-open-dialog.c: create the preview according to the
	users choice of thumbnail size. Doesn't update on changes yet.