zapit, libcoolstream: determine audio mute status

git-svn-id: file:///home/bas/coolstream_public_svn/THIRDPARTY/applications/neutrino-experimental@439 e54a6e83-5905-42d5-8d5c-058d10e6a962

lib/libcoolstream/audio_cs.h

@@ -79,6 +79,7 @@ class cAudio
 		/* volume, min = 0, max = 255 */
 		int setVolume(unsigned int left, unsigned int right);
 		int getVolume(void) { return volume;}
+		bool getMuteStatus(void) { return Muted; }
 
 		/* start and stop audio */
 		int Start(void);