Refactored the shield class (major changes).

Basicaly made the shield class the only place where shield logic exists.
The toggle in control manager was removed. The shield variables in player
entity were removed. And HUD was redirected to look at the item rather
than the player.
Modified the ammo cheat to give full shields too.
Merge branch 'master' of github.com:Bacon41/PantheonPrototype

Conflicts:
	PantheonPrototype/PantheonPrototype/PlayerCharacter.cs