Wrapper class for rigid body removal notifications.
The RigidBodyRemovalNotification class is a wrapper class for marshaling and unmarshaling rigid body removal notifications. When receiving a removal notification this indicates that a shadow copy is no longer needed by the receiving process. A removal notification must only be sent if the receiving process actually has a shadow copy of the concerned body and it must only be sent by the owner and it must only be sent if the owner is sure that the receiving process will no longer need the shadow copy.