Changes to the Cyrus IMAP Server since 2.3.17

      * Fix for incomplete authentication checks in nntpd, reported by
        Secunia as SA46093 - thanks Stefan Cornelius, Secunia Research 

Changes to the Cyrus IMAP Server since 2.3.16

      * Fix for CVE-2011-3208, a remotely exploitable buffer overflow in
        nntpd 

Changes to the Cyrus IMAP Server since 2.3.15

      * Added user_deny.db to be able to selectively deny users access to
        Cyrus services. 
      * Added disconnect_on_vanished_mailbox option. See imapd.conf(5) for
        details 
      * Reworked SQL detection code in configure. See install-upgrade.html
        for more details. 
      * Added popuseimapflags option which enables setting and obeying IMAP
        flags in the POP server. 
      * Added optimized method of handling an empty maildrop in pop3d.
        Requires statuscache to be enabled. (based on work of Cyril Servant
        <elfejoyeux@gmail.com>) 
      * Added annotation_definitions option for specifying external
