message: Fixing a couple of minor mistakes.
diff: @@ -19,12 +19,12 @@ public:
  void checked(bool toggle);
  bool checked() const;
  - ClickCallback& click() { return mCallback; }
  + ClickCallback& click();
  virtual void update() final;
  protected:
  - void onMouseDown(EventHandler::MouseButton button, int x, int y);
  + void onMouseDown(NAS2D::EventHandler::MouseButton button, int x, int y);
  virtual void onFocusChanged() final;
  virtual void onSizeChanged() final;
  