[ODE] world update - best practices?

[Mark Williams]

> Also, the dWorldStep integrator uses no iterations, if that's what you 
> want (note: AFAICT they are iterations in the over-relaxation solver, 
> not sub-steps).
>
>   
What's the relationship (if any) between the "SOR over-relaxation 
parameter" set by dWorldSetQuickStepW and the number of iterations? I'm 
not too experienced with the internals of solvers but would like to be 
able to tweak these parameters in a meaningful way to yield better 
simulations.

Cheers,
Mark