InstrumentSoundShapingView: display info about single-streamed instruments

Until we have a solution for hiding the ENV/LFO tab, display a sensible
message at least.

include/InstrumentSoundShapingView.h

@@ -1,7 +1,7 @@
 /*
  * InstrumentSoundShapingView.h - view for InstrumentSoundShaping class
  *
- * Copyright (c) 2004-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2004-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -30,6 +30,8 @@
 #include "InstrumentSoundShaping.h"
 #include "ModelView.h"
 
+class QLabel;
+
 class EnvelopeAndLfoView;
 class comboBox;
 class groupBox;
@@ -61,6 +63,8 @@ private:
 	knob * m_filterCutKnob;
 	knob * m_filterResKnob;
 
+	QLabel* m_singleStreamInfoLabel;
+
 } ;
 
 #endif