[ODE] plane2d and heightfield examples

[David Walters]

> > The new plane2d and heightfield examples were broken on double precision builds.
> > I've just committed a fix.
>
> Strange - I didn't get an email from svn. Is it just me?
>

Nope, nothing for me either. Also, nothing in the SF check-in mailing
forum thingy : http://sourceforge.net/mailarchive/forum.php?forum_id=48059
but that's usually slow to update.