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 indention everywhere and change code to use Gst.MiniObject.GetObject()
instead of GLib.Opaque.GetOpaque().
It's currently not possible to implement or use GInterfaces on mini objects
but apart from that this should be a great improvement, especially new
mini object classes can be defined in C# now.