expirationWarningThreshold

[Cantor, Scott]

> As we have said in the thread and issue, there really isn't a universally good
> default, it's highly individual.  So if the consensus is that we default it down to
> some very low number (1 ms, etc) so it never really comes into play, and
> therefore requires explicit configuration, then that's OK by me.

Is there a need for it to be on by default? Could it just default to 0 and do nothing until the actual expiration? I haven't looked at the new code so I'm not really up on how it works.

-- Scott