2001-12-16  Sven Neumann  <sven@gimp.org>

	* app/core/gimpcoreconfig.[ch]: changed thumbnail_mode to boolean
	write_thumbnails. thumbnail_mode used to have only two defined
	values; if we need more later, we can change that easily when the
	new GimpConfig system is in place.

	* app/gimprc.c
	* app/file/file-save.c
	* app/gui/file-open-dialog.c
	* app/gui/preferences-dialog.c: changed accordingly.

	* app/config/gimpcoreconfig.[ch]: finished GimpCoreConfig class.