Add DimensionTrait
Reconstruct RigidBodyDriver with trait-based TMP
RigidBodyDriver can support 2D and 3D now. Though relative functions and classes remain to be implemented.
Merge branch 'master' of https://github.com/FeiZhu/Physika
Merge branch 'master' of https://github.com/FeiZhu/Physika
Fix Transform 2d and 3d