[ODE] ode leaks in trimesh

[Geoff Carlton]

I regard to the earlier post of leaks in the trimesh code, I while ago 
when I looked at it there were two distinct issues.

Firstly, for my case I wanted 0 memory allocated at the exit point of 
the program, and so the statics had to manually be cleared with the 
following code:
 dxTriMesh::defaultSphereCache.TouchedPrimitives.Empty();
 dxTriMesh::defaultBoxCache.TouchedPrimitives.Empty();
 dxTriMesh::defaultCCylinderCache.TouchedPrimitives.Empty();

Also, I noted that the dArray didn't appear to call the element's 
destructors on clearing, which is critical.  For the three trimesh 
caches, to avoid a leak you'd have to manually clear each element's 
TouchedPrimitives list before calling resizing the cache array.

However, at that point I stopped working on the prototype with ode and 
I'm not sure whether these issues still exist in the current version - 
when I get around to using trimeshes again I'll make sure.

Geoff