Log Message:
Update to Dovecot 1.1.5.  Changes since 1.1.4:

* Dovecot prints an informational message about authentication problems
  at startup. The message goes away after the first successful
  authentication. This hopefully reduces the number of "Why doesn't
  my authentication work?" questions.

+ Maildir/dbox: Try harder to assign unique UIDVALIDITY values to
  mailboxes to avoid potential problems when recreating or renaming
  mailboxes. The UIDVALIDITY is tracked using dovecot-uidvalidity*
  files in the mail root directory.
+ Many logging improvements
- In some conditions Dovecot could have stopped using existing cache
  file and never used it again until it was deleted.
- pop3 + Maildir: Make sure virtual sizes are always written to
  dovecot-uidlist. This way if the indexes are lost Dovecot will never
  do a huge amount of work to recalculate them.
- mbox: Fixed listing mailboxes in namespaces with prefix beginning
  with '~' or '/' (i.e. UW-IMAP compatibility namespaces didn't work).
- dict quota: Don't crash when recalculating quota (when quota warnings
  enabled).
- Fixes to handling "out of disk space/quota" failures.
- Blocking passdbs/userdbs (e.g. PAM, MySQL) could have failed lookups
  sometimes when auth_worker_max_request_count was non-zero.
- Fixed compiling with OpenBSD