Add corebird-9999 ebuild
Use gnome2-utils instead of gnome2 eclass in corebird 0.6.1

Pulling in the entire gnome2 eclass can cause issues if the package
really isn't a gnome package so we no longer use the gnome2 eclass and
instead manually handle updating the icon cache and recompiling the
gschemas using the tools provided by gnome2-utils