#61 Show mail summary in page title

[Adam McMaster]

In Usermin's mail module, it would be nice if the
mailbox index pages had summary stats (i.e.
total/unread messages) in the page title; this way, it
would be easy to just leave the page open in a
tab/window with the auto-refresh running and be able to
easily see if you have new mail without having to look
at that tab/window.