libvlc should emit playing/pause event when buffering is done

When libvlc is buffering it will emit buffering state events, however, once buffering is done it appears that no explicit state change event is emitted. Hence a libvlc using application could not give reliable UI indication on buffering as it is (in 1.1) not possible to know when buffering is finished. In 1.2 there is also a buffering level property on the event, so there one at least can check if the level has reached 100.

Eitherway an explicit state change from buffering to something else would be very usefu.