message: Properly disconnect the callbacks for all the buttons.
  Could cause a crash after destroying the instance of this window
  (mostly when going back to the main menu)
diff: @@ -12,7 +12,12 @@ GameOptionsDialog::GameOptionsDialog(Font& font)
  GameOptionsDialog::~GameOptionsDialog()
  -{}
  +{
  + btnSave.click().disconnect(this, &GameOptionsDialog::btnSaveClicked);
  + btnLoad.click().disconnect(this, &GameOptionsDialog::btnLoadClicked);
  + btnReturn.click().disconnect(this, &GameOptionsDialog::btnReturnClicked);
  + btnClose.click().disconnect(this, &GameOptionsDialog::btnCloseClicked);
  +}
  void GameOptionsDialog::init()
  