for loading ui themes as icon themes. Add a list in both
	  theme load functions to avoid dupplicates. Read extra ui
	  theme information from the index.theme file if available.
	  Store the theme name (folder name) and display name separatly
	  in the store, authors can define another theme name in the
	  index.theme file which will result in settings a theme
	  that is not recognized by Gtk. Use hicolor as default icon
	  theme name. Fix the icon theme directory that was pushed
	  (its $datadir/icons, not $datadir/xfce4/icons).

(Old svn revision: 27205)