* gets Mutt to properly log off the IMAP server when quitting. Clients
  don't care, but it's polite and proper.
* further updates the flags changes from yesterday
* uses CLOSE instead of EXPUNGE when closing a mailbox and purging
  messages, for some slight speed gain.
* purges all messages marked for deletion in one command (if purging),
  making for very cool speed gains switching mailboxes if you're on,
  say, a few high volume mailing lists. Yeah, baby! (I personally love
  this one).

(From Brendan Cully <brendan@kublai.com>)