GLib misses propper management of unmanaged resources

[badcel]

If it is decided wether we use SafeHandle or not (see #198) we need to work on the GLib classes. They do not inherit from GObject and thus do not inherit the memory management features. Those which are implemented by us (e.g. MainLoop and MainContext) do not have any automated management of the unmanaged resources meaning they are never freed if the garbage collector removes them.