Fixed rotation bug, issue # 4: The app now successfully hosts the Unity View as a subView, and properly rotates it when the device is rotated.

Changes:
	- ARMPlayViewController has a new method: addUnityViewController:unityView: that adds a view controller as a child view controller, and adds the view as a subview (sent to the back) to the main view.
	- ARMPlayViewController overrides the methods “viewWillRotate…” and “viewDidRotate…” and forwards the message to its child view controller (the unity view controller)
		- This should happen by default, but for some reason it doesn’t.
	-ARMAppController calls ARMPlayViewController’s addUnityViewController:unityView: with an instance of UnityDefaultViewController