+ Constraint hollow class.

the mathematician-friendly [w x y z].

Added lol::phys::Simulation, lol::phys::EasyPhysics for easy physic uses.
Added PhysicsObject, wich hold EasyMesh & EasyPhysics components so it is easy to use. Easy seems to be the consensus.
BtPhysTest now works with new physics classes.

Known problem for this commit:
Physics is not properly setup.
There might be memory leaks, I don't think I've parsed all new/delete.
A LOT of primitives are not taken into account.