[Python-3000] Support for PEP 3131

["Martin v. Löwis"]

> Python currently provides to everyone the restriction of
> identifiers to a character set that everyone knows and trusts.
> Many of us want Python to continue to provide such restriction
> for those who want identifiers to be in a character set they
> know and trust.  This is not incompatible with your desire to
> permit alternative character sets, as long as Python offers an
> option to make that choice.  We can continue to discuss the
> details of how that choice is expressed, but this general idea
> is a solution that would give us both what we want.
> 
> Can we agree on that?

So far, all proposals I have seen *are* incompatible, or had
some other flaws, so I'm not certain that this general idea
provides a non-empty solution set.

Regards,
Martin