[Python-3000] Simplifying the copy protocol

[Raymond Hettinger]

From: "Guido van Rossum" <guido at python.org>
>I haven't had the time to look into this, but it sounds unintuitive to
> drop __reduce_ex__ which is supposed to be the "extended" IOW "newer"
> version of the API compared to __reduce__ which was deemed to be
> missing something.

Right.  The version argument should be kept.
Recommend renaming __reduce_ex__ to  __reduce__
and dropping the older method.


Raymond