* Removed Arena Utility, it was using an antiquated singleton.
* Created Constants.Dice enum for dice rolls.
* Rearranged classes
* Extracted enums from constants class
* Adding extracted enums
* tidy up - rejigged controllers/services
* added thymeleaf
* extracted ArenaManagerIF interface
* changes ArenaManager to a 'Component' (not a service/controller)
* adding missing interface
* moved ArenaManager into Controller package
* renamed PickController to PickService
* rewired the configuration/autoconfiguration
* fixed broken library logic
* sorting out the controller