Engine refactored other changes

- Engine:refreshEngine replaced by Engine:componentAdded and Engine:componentRemoved
- Engine.entities refactored. Entities now get normal ids. If an entity gets deleted
its id is saved in Engine.stack and used as key for the next entity added to the engine.
- Engine[component.__name] refactored. Entities now have their id as key for fast access
- refactored all functions in Engine for new Entitylists
- System.targets now has entity ids as keys
- Playercreation moved to LevelOneState
- Entity creation in LevelOne now uses local wall istead of self.wall
- engine:refreshEntity replaced in events and systems