Now have three varieties of the Meter Toolbar.

We have separate record and play meters.  The original kind of meter is now called a combined meter.  I've kept it because it can be useful when undocked if you do want both meters.  I've also fixed it so that if made very narrow the meters stack vertically just as they already did horizontally.

src/toolbars/ToolManager.h

@@ -57,7 +57,7 @@ class ToolManager:public wxEvtHandler
    bool IsVisible( int type );
 
    void ShowHide( int type );
-
+   void Hide( int type );
    void Expose( int type, bool show );
 
    ToolBar *GetToolBar( int type ) const;