There are three types of solution used: adding the new keyword to the member
in the subclass, renaming the subclass member to avoid name collision and
removing the subclass member if the functionality is the same.
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.