Revision 884263

- update to vers, 2.4.18
  * This fixes security issue, bug #16823
- and these upstream bugs
  * Security fix: handle urlfetch range starting outside message range
  * A bunch of cleanups and fixes to compiling
  * A bunch of sieve cleanups
  * Enhanced SSL/TLS configuration options
  * Disable use of SSLv2/SSLv3
  * Allow SQL backend for mboxlist and statuscache (thanks Julien Coloos)
  * Fixed Task #116: correct LIST response for domains starting with ‘inbox.’
  * Fixed Task #76: fixed lmtpd userdeny db checks (thanks Leena Heino)
  * Fixed bug #3856: lmtpd now performs userdeny checks
  * Fixed bug #3848: support charset aliases in encoded headers
  * Fixed bug #3853: disconnect_on_vanished_mailbox: release mailbox lock before exiting (thanks Wolfgang Breyha)
  * Fixed bug #3415: fixed nntpd LIST/GROUP bug
  * Fixed bug #3784: no longer crash in THREAD REFERENCES when messages reference themselves
  * Fixed bug #3757: don’t segfault on mailbox close with no user