PianoRoll: reset last note volume/panning when clearing project

In order to get a uniform behaviour when starting with a new project or
opening another project, reset volume and panning of last edited note so
new placed notes have default volume and panning.

Closes #644.

src/core/song.cpp

@@ -749,6 +749,11 @@ void song::clearProject()
 		engine::automationEditor()->setCurrentPattern( NULL );
 	}
 
+	if( engine::pianoRoll() )
+	{
+		engine::pianoRoll()->reset();
+	}
+
 	m_tempoModel.reset();
 	m_masterVolumeModel.reset();
 	m_masterPitchModel.reset();

src/gui/PianoRoll.cpp

@@ -641,6 +641,15 @@ PianoRoll::PianoRoll() :
 }
 
 
+
+void PianoRoll::reset()
+{
+	m_lastNoteVolume = DefaultVolume;
+	m_lastNotePanning = DefaultPanning;
+}
+
+
+
 void PianoRoll::changeNoteEditMode( int i )
 {
 	m_noteEditMode = (noteEditMode) i;