[ODE] Updating trimesh data.

[david.reyes]

Hi.

I've noticed that when once created a trimesh if I update the trimesh 
data trough the function "dGeomTriMeshSetData", the trimesh AABB wasn't 
being updated.

I don't know if that is meant to be this way or I'm missing something. 
So I added the next line of code to the "dGeomTriMeshSetData" function.

((dxTriMesh*)g)->gflags |= GEOM_AABB_BAD;

It's also possible that should have the flag "GEOM_DIRTY".

Looking forward to your answers.

Thanks.

David Reyes i Forniés.