Extracted the containment of multiple engines from the Simplicity
namespace to a CompositeEngine class.
Improvements to the rendering API.
Added the ability to retrieve engines and world representations from
Simplicity.
Improvements to the rendering API.
Added the WindowEngine interface.
Removed rogue 'using' statements from .ttp files!
Optimizations :)
More work on model subtraction.
Refactored subtraction.
Subtraction working! But not for all cases... needs more cubeMinusCube
testing...