[ODE] Should trimeshes react to physics?

[Marco Grubert]

> That happens when you have lots of small, connected cubes colliding 
> against a larger cube, too. You have to filter contacts on a per-body 
> basis, no matter where those contacts are coming from.

I am filtering out similar contacts and create the convex hull for each 
body. For a highly tesselated terrain this reduces the number of contacts 
from an average of 20 to 6. However, the real problem that causes explosions 
is conflicting contacts where at a slope contacts are generated with 
differing normals such as one pointing straight up and another one nearby 
pointing diagonally upwards.

- Marco