Level Map Camera locked to square aspect ratio

- LockSquareAspectRatio:
-- can now center the camera viewport on a point
-- checks if attached camera is active before changing its viewport
-- checks if the aspect ratio has changed before updating the camera viewport
- ActivateMap:
-- enabling/disabling camera is now done within Update()
Merge remote-tracking branch 'origin/maptest' into maptest

Conflicts:
	Assets/Minimap/LockSquareAspectRatio.cs