URBNG-68, URBNG-70 Games list and Create new game

Changes:
- Redefined actions in Game controller
- Moved a few methods from controller to models.dal.Bridges
- Modified some methods in models/classes/Games.scala to throw Success or Failure
- Added new functionalities:
     - cancel the game when game's status == published in 'Games list' view (with confirmation messagebox)
     - publish the game in 'Create new game' view (with confirmation messagebox)
     - edit the game when game's status == project or published
- Added confirmation messagebox to 'delete the game' ('Games list' view)
- Modified 'combineDate' method in models/classes/mutils.scala as suggested earlier (in https://github.com/blstream/UrbanGame/pull/63)
- Small changes in database structure (e.g. added raw version of Skins table)