[Python-3000] optimizing [x]range

["Martin v. Löwis"]

> The patch is based on the latest trunk/ checkout, Python 2.6. I don't 
> think this is a problem if nobody else made any effort towards making 
> xrange more sequence-like in the Python 3000 branch. The C source might 
> require some tab/space cleanup.

Unfortunately, this is exactly what happened: In Py3k, the range object
is defined in terms PyObject*, so your patch won't apply to the 3k branch.

Regards,
Martin