hack to fix start on MiniMenu

(I have some thoughts to clean this up, on the lines of allowing NextScreen
to expicitly say "pop a screen", but I need to think about it some more.)

stepmania/src/ScreenMiniMenu.h

@@ -88,6 +88,7 @@ class ScreenMiniMenu : public ScreenOptions
 public:
 	static void MiniMenu( MenuDef* pDef, ScreenMessage smSendOnOK, ScreenMessage smSendOnCancel = SM_None, float fX = 0, float fY = 0 );
 
+	void BeginScreen();
 	void LoadMenu( const MenuDef* pDef );
 	void HandleScreenMessage( const ScreenMessage SM );