glib-sharp will only get a new release with the new API that we need for
3.0 in a year or something. Instead of waiting a year before we can release
something we now have our own internal copy of glib-sharp trunk that will
be dropped once glib-sharp 3.0 is released.
Everything is now compilable and working without any additional patches.
Also fix some reference ownership issues in the StaticPadTemplate bindings
and make them a read-only container without any way to create new instances.
We don't need StaticCaps anywhere and StaticPadTemplates only for reading
the static pad templates of an element factory.
