[ODE] triangle collider surface

[Erwin de Vries]

> The original problem, which didn't crash but also didn't generate any
> contacts, was due to my building ODE with dDOUBLE defined.  There's a
> couple places in the tri-collide code that expert pointers to arrays of
> floats, e.g. from dGeomGetPosition.

That was actually a bug on my side indeed. I fixed it in a lot of places,
but forgot a few. Its not that difficult to fix anyway.

Hope it works for you.

Erwin