[Dovecot] 1.0.beta7

Sorry, the authentication problem still wasn't actually fixed in beta6. Now, this time I tested every possible authentication case that it really works.

I'll soon create a CVS branch which is going to stabilize into the 1.0 release. I won't add new features there so it shouldn't really get broken anymore, at least because of new features..

So, two changes in this release:

    + Added shutdown_clients setting to control if existing imap/pop3
      processes should be killed when master is.
    - Master login fixes, PLAIN authentication was still broken..