[Python-3000] Using range()

["Martin v. Löwis"]

> It is a bit surprising, especially given
> that the following works:
> 
>>>> r = range(10**19-100, 10**19)
>>>> r[0]
> 9999999999999999900

The original example fails because range_length() overflows
in range_item.

Given that range_item is "almost" there, it's probably not
as difficult to fix this as I first thought: range_item should
use range_length_obj, and compare to rem.

Contributions are welcome.

Regards,
Martin