message: Disable difficulty selection dialog
  This is a temporary change since difficulty is not yet implemented. This is also not the way I originally intended to implement difficulty selection though I'm open for discussion on this. Will open a new issue to discuss.
diff: @@ -228,10 +228,11 @@ void MainMenuState::btnNewGameClicked()
  disableButtons();
  - dlgNewGame.show();
  -
  + //dlgNewGame.show();
  + wasDifficultyOkClicked();
  }
  +
  void MainMenuState::wasDifficultyOkClicked()
  {
  mReturnState = new PlanetSelectState();
  @@ -240,11 +241,13 @@ void MainMenuState::wasDifficultyOkClicked()
  Utility<Mixer>::get().fadeOutMusic(constants::FADE_SPEED);
  }
  +
  void MainMenuState::newGameCancelled()
  {
  enableButtons();
  }
  +
  /**
  * Click handler for Continue button.
  */
  