Piano roll GUI enhancements. Reset LFO counter on song start

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@935 0778d3d1-df1d-0410-868b-ea421aaaa00d

include/controller.h

@@ -70,7 +70,7 @@ public:
 		return tLimit<float>( _val, 0.0f, 1.0f );
 	}
 
-	static int runningFrames();
+	static unsigned int runningFrames();
 	static float runningTime();
 
 	static void triggerFrameCounter( void );