[ODE] Fixed stepping

[Jon Watte (ODE)]

Geoff Carlton wrote:
> Hi,
> I don't think its a good idea to fundamentally change the way all 
> existing (correct) code works, which may well be implementing fixed 
> stepping logic outside ODE.   Two ideas:
>   

I actually think it is. This is SUCH a common problem, that we can break 
the code. It's not like it would be hard to fix in the cases where you 
actually want to compile something old.

Btw: I think the world stepping function should take a world id, and an 
integer count of number of steps.

Cheers,

          / h+