Updated script parameters in Enemy prefabs

- Set sprite selector prefix parameters
- Set controller to have HasGun set to true
Updated SpriteSelector, corrected EnemyController

- Changed EnemyController to directly modify MoveVector
- SpriteSelector looks for generic EntityController
- EntityController is now abstract to prevent accidental instantiations
- SpriteSelector no longer requires EntityController as a requirement
Merge branch 'master' of github.com:dpek/cs354s-teleport-man
Added logo graphic to UISpriteCollection

- Also increased padding in UISpriteCollection
Updated Main scene to use new menu UI assets