game finish dialog: refactoring
intro: simplify PhysicalStoneEffect.render
renderer: optimize BoardRenderer.renderStone
view: refactoring, use less synchronized
game menu dialog: disable resume if resume is not possible
view: always show empty board if no game is running
game: change order of windows again: main menu is above game view

disable resume button, if not available
game: always show main menu options menu item to show game menu dialog
intro: move word up so that stones fly into camera