[Dovecot] 1.1.9 release candidate

http://dovecot.org/tmp/dovecot-1.1.9.rc.tar.gz

There are a couple of a bit larger changes, so would be nice if a few people tested this on different setups before I released the final v1.1.9.

Changes since v1.1.8:

+ deliver: Added rejection_subject setting, which is used for
  rejected mails.
+ pop3: Prevent clients from looping forever trying to fetch an
  expunged message.
+ If login process crashes, log the IP address that (maybe) caused it.
+ If core dump limit is 0, add "core dumps disabled" to startup log line.
- mbox: Fixed assert-crash with pop3_lock_session=yes
- dbox: Fixes to handling maildir-converted files.
- Auth cache wasn't working correctly for all fields (e.g. allow_nets)
  with blocking passdbs (e.g. mysql).
- pgsql: Handle reconnecting to server without failing auth lookups.
- Berkeley DB memory/resource leak fixes.
- maildir: Fixes to handling over 26 keywords.