Added reset capability to audio outputs that dispatches an audiostop

event so that the audio panel gui component can reset when an audio
source has been removed due to activity timeout.

src/audio/AudioManager.java

@@ -294,6 +294,7 @@ public class AudioManager implements Listener<AudioPacket>, IAudioController
 		public void dispose()
 		{
 			mAudioOutput.removeAudioEventListener( this );
+			mAudioOutput.reset();
 			mAudioOutput = null;
 		}
 		

src/audio/output/AudioOutput.java

@@ -29,6 +29,12 @@ public abstract class AudioOutput implements Listener<AudioPacket>
 	protected boolean mCanProcessAudio;
 	protected long mLastActivity;
 
+	public void reset()
+	{
+		broadcast( new AudioEvent( AudioEvent.Type.AUDIO_STOPPED, 
+				getChannelName() ) );
+	}
+	
 	public void dispose()
 	{
 		mCanProcessAudio = false;