Refactored to support qml-box2d's transition to qboject based bodies
and target properties.  Added PhysicsEntity and some Box2D Body/Fixture
convienence components.  Entity and Sprite no longer inherit from Box2DBody.
Cleanup based on review
Fix the fixture geometry in some examples and dropped the gamescene example, it isn't relevant anymore.
I think scene isn't set in time for this, using parent.scene works.
Ensure the qml files get copied to the build dir
Fixed install of plugin.qmltypes and dropped an unused include
Merge pull request #85 from kenvandine/box2d-reboot

Refactored to support qml-box2d's transition to qboject based bodies