[ODE] Heightfield / ray

[David Walters]

> Anyway I submitted the patch on sourceforge that fixes that and the
> previously reported problem, as the bug submitter had been kind enough
> to send me a test file.

I've just applied this patch and set its status to pending - (which,
in case people are unfamiliar with the sourceforge tracker, means in
14 days it'll auto-close).

Could people please re-test with SVN revision #1175 or later to give
more test coverage - I've tested demo_heightfield only. I assume it's
all fine, but just to be certain!

Regards,
David