added toggle-button for controller-rack-view and improved default positions of sub-windows in workspace

git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@1254 0778d3d1-df1d-0410-868b-ea421aaaa00d

include/main_window.h

@@ -109,6 +109,7 @@ public slots:
 	void toggleProjectNotesWin( void );
 	void toggleFxMixerWin( void );
 	void togglePianoRollWin( void );
+	void toggleControllerRack( void );
 
 	void undo( void );
 	void redo( void );