Rewrote the class TowerPlacerAI

Rewrote the class TowerPlacerAI i a new class AiTowerPlacer. Hade null
pointer on three places and needed checker if it is empty or contains
towers the first time u call getNewTowers()
Tower placer ai test
Delate syso. func
Add line
AI Tower Placer Tester
Fix but fail
class to test