Re: remove 'exit'?

[Karl Berry]

FWIW, I also agree with just removing the module instead of trying to
ever-escalate warnings.  My experience is that few people are likely to
deal with it until it becomes an error regardless of warning.

I would agree even more with keeping the module as an "alias" for stdlib
so as to avoid this seemingly-gratuitious backward incompatibility, but
nobody suggested that, so I guess I won't :).

k