Improved Face interface.
Clarified some comments in the Positionable interface.
Clarified the Sizable interface comments.
Clarified the tangible interface.
Clarified the Decor interface.
Added comments to the GridDecor interface.
Improved Entity interface documentation and tweaked method returns.
Added documentation to GridEntity an removed inappropriate method.
Clarified OrthoBoundEntity interface documentation.
Updated camera interface documentation.
Clarified the Camera interface documentation.