Add flags BOX_SHAPE_HAS_MASS and BOX_SHAPE_HAS_COLLISION_SHAPE_TYPE to CMD_CREATE_RIGID_BODY
(which maps to CMD_CREATE_BOX_COLLISION_SHAPE for backward compatibility for now)
Need to add way to receive world transform
(force/torque sensor needs new API)
in a nutshell, users of shared memory physics API should not
directly poke into shared memory, not fill 'SharedMemorCommand'
nor read SharedMemoryStatus directly. The C-API declares 'handles' for those,
to avoid it from happening.
