Fixes the switching of the playback device in calls upon hotplugging.

src/org/jitsi/impl/neomedia/MediaServiceImpl.java

src/org/jitsi/impl/neomedia/device/AudioSystem.java

.../neomedia/jmfext/media/protocol/portaudio/DataSource.java

...impl/neomedia/jmfext/media/renderer/AbstractRenderer.java

...ia/jmfext/media/renderer/audio/AbstractAudioRenderer.java

...omedia/jmfext/media/renderer/audio/PortAudioRenderer.java

...media/jmfext/media/renderer/audio/PulseAudioRenderer.java

src/org/jitsi/util/event/PropertyChangeNotifier.java