message: Use new delegate Button constructor in MainMenuState
diff: @@ -16,11 +16,11 @@ using namespace NAS2D;
  MainMenuState::MainMenuState() :
  mBgImage("sys/mainmenu.png"),
  - btnNewGame{constants::MAIN_MENU_NEW_GAME},
  - btnContinueGame{constants::MAIN_MENU_CONTINUE},
  - btnOptions{constants::MAIN_MENU_OPTIONS},
  - btnHelp{constants::MAIN_MENU_HELP},
  - btnQuit{constants::MAIN_MENU_QUIT},
  + btnNewGame{constants::MAIN_MENU_NEW_GAME, {this, &MainMenuState::onNewGame}},
  + btnContinueGame{constants::MAIN_MENU_CONTINUE, {this, &MainMenuState::onContinueGame}},
  + btnOptions{constants::MAIN_MENU_OPTIONS, {this, &MainMenuState::onOptions}},
  + btnHelp{constants::MAIN_MENU_HELP, {this, &MainMenuState::onHelp}},
  + btnQuit{constants::MAIN_MENU_QUIT, {this, &MainMenuState::onQuit}},
  lblVersion{constants::VERSION},
  mReturnState(this)
  {}
  @@ -48,24 +48,19 @@ void MainMenuState::initialize()
  btnNewGame.fontSize(constants::FONT_PRIMARY_MEDIUM);
  btnNewGame.size({200, 30});
  - btnNewGame.click().connect(this, &MainMenuState::onNewGame);
  btnContinueGame.fontSize(constants::FONT_PRIMARY_MEDIUM);
  btnContinueGame.size({200, 30});
  - btnContinueGame.click().connect(this, &MainMenuState::onContinueGame);
  btnOptions.fontSize(constants::FONT_PRIMARY_MEDIUM);
  btnOptions.size({200, 30});
  btnOptions.enabled(false);
  - btnOptions.click().connect(this, &MainMenuState::onOptions);
  btnHelp.fontSize(constants::FONT_PRIMARY_MEDIUM);
  btnHelp.size({200, 30});
  - btnHelp.click().connect(this, &MainMenuState::onHelp);
  btnQuit.fontSize(constants::FONT_PRIMARY_MEDIUM);
  btnQuit.size({200, 30});
  - btnQuit.click().connect(this, &MainMenuState::onQuit);
  mFileIoDialog.setMode(FileIo::FileOperation::Load);
  mFileIoDialog.fileOperation().connect(this, &MainMenuState::onFileIoAction);
  