tools are actually used.
This commit replaces
MODGNOME_DESKTOP_FILE with MODGNOME_TOOLS += desktop-file-utils
MODGNOME_MIME_FILE with MODGNOME_TOOLS += shared-mime-info
MODGNOME_ICON_CACHE with MODGNOME_TOOLS += gtk-update-icon-cache
(some prettyfication will follow shortly)
instead. It is just too hard to maintain a coherent list of still
reachable homepages for GNOME projects so use wiki.gnome.org which is
the entry point for *all* GNOME apps.