message: Move deleted copy and assignment members to public
  This seems to be a holdover from before delete was possible, in which
  case declaring the members private would produce errors if they were
  ever used.
diff: @@ -11,15 +11,13 @@ public:
  public:
  GameOverDialog();
  + GameOverDialog(const GameOverDialog&) = delete;
  + GameOverDialog& operator=(const GameOverDialog&) = delete;
  ClickCallback& returnToMainMenu() { return mCallback; }
  void update() override;
  -private:
  - GameOverDialog(const GameOverDialog&) = delete;
  - GameOverDialog& operator=(const GameOverDialog&) = delete;
  -
  private:
  void btnCloseClicked();
  