[ODE] Rope Simulation

[conn@smsc.no]

> I got quite good result playing around with ERP/CFM check out
> http://ezphysics.org
> the demo does look like a rubbery kind of rope but for less rubbery
> results I increased the weight of the capped cylinders composing the rope.

I'll check the code out after the weekend. My experience also showed that
i could get a more stable rope by changing the mass of the capped
cylinders, but this leads to other problems. Collision reponse between the
rope and another object will change, if theres a engine controlling the
rope, different forces has to be used depending on the mass of the capped
cylinders and so on