Fix modal body initial velocity

This branch fixes an issue which may cause incorrect initial velocities and angular velocities of a modal node connected to a rigid body. The purpose of this branch is just to eliminate an invalid call to DynamicBody::SetValue which may execute the following two lines at the wrong time:

	X.Add(iFirstIndex + 1, V*dMass + W.Cross(STmp));
	X.Add(iFirstIndex + 4, STmp.Cross(V) + JTmp*W);