Move the DroomsGame back to impl so it can be shared between GUI and laucher

 * main class in game-launcher renamed to DroomsGameLauncher and left with simple
   main which is just using the DroomsGame from impl
 * added getPlayground() to DroomsGame as its needed in swing-gui
Remove launcher-game dependency from launcher-tournament
Merge pull request #8 from psiroky/game-launcher-fix

Move the DroomsGame back to impl, so it can be shared between GUI and launchers