shutdown

Makes libwnck stop listening to events and tear down all resources from libwnck.

This should be done if you are not going to need the state change notifications for an extended period of time, to avoid wakeups with every key and focus event.

After this, all pointers to Wnck object you might still hold are invalid.

Due to the fact that Wnck objects are all owned by libwnck, users of this API through introspection should be extremely careful: they must explicitly clear variables referencing objects before this call. Failure to do so might result in crashes.