Physics integration

• In order to have 3d objects interact in compelling ways.
• As a Qt Developer
• I want to be able to use physics simulations in my applications.

Solution Assumptions:

• Bullet3D?
• Physics environments will be cleaned up automatically
• Only 1 physics environment
• A given entity will be controlled by either the QML or Physics engine, not both (dichotomous control)
• A 1:1 Mapping between Item3Ds? and physics objects is acceptable if it makes the API or implementation better or easier.
• updates to the physics simulation apply to the next physics update