Initial commit of redesigned internal processing and audio management.

Note: Several of the decoders are currently non-functioning in this
commit.  If you want the latest functioning codebase, please checkout
the commit prior to this one.  All decoders will eventually be updated
with this new architecture.

Currently broken:
- Logging and recording
- Aux decoders (Fleetsync/MDC/LoJack/Tait)
- LTR/Passport decoders

Changes in this commit:
- Module architecture for decoders and components with central
provisioning by the DecoderFactory
- Transition from Complex sample stream processing to float buffer
processing for improved memory management
- Redesigned filter structures - to support buffers and streams
- Resolved several memory leak issues
- Universal sharing of the thread pool manager
- Added centralized audio management with call/user prioritization and
new gui with mute/volume controls
- Embedded audio metadata for eventual streaming support
- Redesigned ProcessingChain to support independent re-use
- Added new TrafficChannelManager to handle traffic channel allocations
- Traffic Channel pool size and Call timeout available in P25 and
MPT1327 configs
- Redesigned channel and decoder gui components

src/audio/output/AudioOutput.java

@@ -0,0 +1,84 @@
+package audio.output;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import javax.sound.sampled.BooleanControl;
+import javax.sound.sampled.FloatControl;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import sample.Broadcaster;
+import sample.Listener;
+import audio.AudioEvent;
+import audio.AudioPacket;
+import audio.metadata.AudioMetadata;
+
+public abstract class AudioOutput implements Listener<AudioPacket>
+{
+	private final static Logger mLog = LoggerFactory.getLogger( AudioOutput.class );
+	
+	private AtomicBoolean mSquelched = new AtomicBoolean( false );
+	private Listener<AudioMetadata> mAudioMetadataListener;
+	protected Broadcaster<AudioEvent> mAudioEventBroadcaster = new Broadcaster<>();
+
+	public void dispose()
+	{
+		mAudioEventBroadcaster.dispose();
+		mAudioEventBroadcaster = null;
+		mAudioMetadataListener = null;
+	}
+	
+	public abstract String getChannelName();
+	
+	public abstract BooleanControl getMuteControl();
+	public abstract boolean hasMuteControl();
+	
+	public abstract FloatControl getGainControl();
+	public abstract boolean hasGainControl();
+	
+	protected void broadcast( AudioMetadata metadata )
+	{
+		if( mAudioMetadataListener != null )
+		{
+			mAudioMetadataListener.receive( metadata );
+		}
+	}
+	
+	public void setSquelched( boolean squelched )
+	{
+		mSquelched.set( squelched );
+	}
+	
+	public boolean isSquelched()
+	{
+		return mSquelched.get();
+	}
+	
+	/**
+	 * Registers a single listener to receive audio start and audio stop events
+	 */
+	public void addAudioEventListener( Listener<AudioEvent> listener )
+	{
+		mAudioEventBroadcaster.addListener( listener );
+	}
+	
+	public void removeAudioEventListener( Listener<AudioEvent> listener )
+	{
+		mAudioEventBroadcaster.removeListener( listener );
+	}
+	
+	/**
+	 * Registers a single listener to receive the audio metadata from each 
+	 * audio packet
+	 */
+	public void setAudioMetadataListener( Listener<AudioMetadata> listener )
+	{
+		mAudioMetadataListener = listener;
+	}
+	
+	public void removeAudioMetadataListener()
+	{
+		mAudioMetadataListener = null;
+	}
+}