Resolves #170 adding support for Airspy Mini tuner's 3 and 6 MHz

sample rates.

Resolves issue in PolyphaseChannelManager responding to sample rate
changes in the tuner.  The manager now recreates the channelizer when
needed if the tuner's sample rate has changed since the last time the
channelizer was used.

Updates the Tuner selection view to reflect tuner lock state.  Updates
the tuner editors to enable/disable frequency controller and sample
rate controls according to the tuner's lock state.

src/main/java/io/github/dsheirer/source/tuner/TunerEvent.java

@@ -2,33 +2,34 @@ package io.github.dsheirer.source.tuner;
 
 public class TunerEvent
 {
-	private Tuner mTuner;
-	private Event mEvent;
-	
-	public TunerEvent( Tuner tuner, Event event )
-	{
-		mTuner = tuner;
-		mEvent = event;
-	}
-	
-	public Tuner getTuner()
-	{
-		return mTuner;
-	}
+    private Tuner mTuner;
+    private Event mEvent;
 
-	public Event getEvent()
-	{
-		return mEvent;
-	}
-	
-	public enum Event
-	{
-		ADD,
-		REMOVE,
-		CHANNEL_COUNT,
-		FREQUENCY,
-		SAMPLE_RATE,
-		REQUEST_MAIN_SPECTRAL_DISPLAY,
-		REQUEST_NEW_SPECTRAL_DISPLAY;
-	}
+    public TunerEvent(Tuner tuner, Event event)
+    {
+        mTuner = tuner;
+        mEvent = event;
+    }
+
+    public Tuner getTuner()
+    {
+        return mTuner;
+    }
+
+    public Event getEvent()
+    {
+        return mEvent;
+    }
+
+    public enum Event
+    {
+        ADD,
+        LOCK_STATE_CHANGE,
+        REMOVE,
+        CHANNEL_COUNT,
+        FREQUENCY,
+        SAMPLE_RATE,
+        REQUEST_MAIN_SPECTRAL_DISPLAY,
+        REQUEST_NEW_SPECTRAL_DISPLAY;
+    }
 }