[Mailman-Developers] make admin password sticky

[Brian Edmonds]

I would find it really handy if Mailman would set a special cookie when
I authenticate to a list's admin page with the Mailman admin password,
so that it would then let me in to all other lists without prompting for
a password.  I often go through a bunch of lists at a time clearing out
the non-member spam posts from the admin approval queue, and it would be
nice to not have to type passwords over and over.

Brian.