[ODE] reentrant code?

[Mathias Broxvall]

> ODE is not thread-safe. If you might be able to get away with using a
> separate world and space for each thread, but I have not tried this.

Thanks for your answer. 

I tried running it with separate a separate world and space for each thread 
when I got the errors but to no avail. My current "solution" to this was to 
instead create separate processes (fork) for the different work threads and 
to use shared memory and pipes between the processes for non ODE related 
states. This worked very well and, of course, gives no problems with ODE.

again, thanks

/ Mathias