Resolves #372 - Icecast reconnect following network outage. Updates

the lost connection timeout from default of 60 seconds down to 5 seconds
so that the connection state updates more quickly.  Removed complex
error handling and replaced with a simpler approach to catch an error
and disconnect and then attempt a reconnect.

Added new 'Network Unavailable' error state that detects when the network
connection is unavaialable.

Updated the icecast metadata updater to close the TCP session after
successfully writing metadata to the socket.

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

@@ -70,6 +70,11 @@ public enum BroadcastState
      */
     MOUNT_POINT_IN_USE("Mount Point In Use", false),
 
+    /**
+     * Network is unavailable or the server address cannot be resolved
+     */
+    NETWORK_UNAVAILABLE("Network Unavailable", false),
+
     /**
      * Server is not known or reachable
      */