[ODE] Memory management

[Joe Ante]

> That's right, but I don't see the benefit in an option
> to turn it off when we could have an (API) option to
> reseed it instead for the same effect (repeatability)
> without the loss of stability.
Equally important for replayability is that you add your
joints/bodies/colliders in the same order into the system as they were
stored when you last left the simulation.

This is necessary since the initial ordering of the bodies in the world
changes the order in which the joints are processed. Which of course affects
the random reordering.

Joachim Ante