Improvements to icecast failure handling (#1401)

- Add mechanism to persist failure reason while continuing to reconnect
- Add 'warning' attribute for failure conditions that may be temporary,
  but still need to be reported
- Add logging for failures
- Prevent possibly temporary server-side conditions from blocking
  reconnect attempts
- Detect icecast 2.4 auth failures
- Prevent generic errors from overriding existing error state

src/main/java/io/github/dsheirer/audio/broadcast/ConfiguredBroadcast.java

@@ -37,6 +37,7 @@ public class ConfiguredBroadcast
     private BroadcastConfiguration mBroadcastConfiguration;
     private AbstractAudioBroadcaster mAudioBroadcaster;
     private ObjectProperty<BroadcastState> mBroadcastState = new SimpleObjectProperty<>();
+    private ObjectProperty<BroadcastState> mLastBadBroadcastState = new SimpleObjectProperty<>();
 
     /**
      * Constructs an instance
@@ -89,6 +90,14 @@ public class ConfiguredBroadcast
         return mBroadcastState;
     }
 
+    /**
+     * Last bad broadcast state of the configured audio broadcaster (optional)
+     */
+    public ObjectProperty<BroadcastState> lastBadBroadcastStateProperty()
+    {
+        return mLastBadBroadcastState;
+    }
+
     /**
      * Sets the audio broadcaster
      * @param audioBroadcaster to use for this configuration
@@ -96,11 +105,13 @@ public class ConfiguredBroadcast
     public void setAudioBroadcaster(AbstractAudioBroadcaster audioBroadcaster)
     {
         mBroadcastState.unbind();
+        mLastBadBroadcastState.unbind();
         mAudioBroadcaster = audioBroadcaster;
 
         if(audioBroadcaster != null)
         {
             mBroadcastState.bind(mAudioBroadcaster.broadcastStateProperty());
+            mLastBadBroadcastState.bind(mAudioBroadcaster.lastBadBroadcastStateProperty());
         }
         else
         {
@@ -120,6 +131,7 @@ public class ConfiguredBroadcast
             {
                 mBroadcastState.setValue(BroadcastState.CONFIGURATION_ERROR);
             }
+            mLastBadBroadcastState.setValue(null);
         }
     }