Game, Players, and InterfaceWithGame interface

A lot of new structure here, mainly the ```Game``` class which holds an instance of a game and runs it through the turns, the ```Player``` which holds a list of owned tanks on the field that determine whether the player is still alive and also gives orders to those tanks, and the ```InterfaceWithGame``` java interface, which describes a user interface (like a gui) for a game instance, from displaying sprites, to getting orders from human players for ```HumanPlayer```, to displaying the winner.

```GameTest``` is essentially a stand-in for the main gui menu program that will let users select game options and launch games.