[Dovecot] v2.1.9 released

[Timo Sirainen]

http://dovecot.org/releases/2.1/dovecot-2.1.9.tar.gz
http://dovecot.org/releases/2.1/dovecot-2.1.9.tar.gz.sig

I've again mostly finished reading and answering most of the mails in
Dovecot mailing list. There are a couple annoyingly difficult / time
consuming bugreport mails that I haven't replied to yet, but if anyone
thinks I should have replied to something already feel free to resend
the mail.

For the new Redis/memcached dict stuff see
http://master.wiki2.dovecot.org/AuthDatabase/Dict and
http://master.wiki2.dovecot.org/Quota/Dict

I'm thinking about removing the new quota_ignore_save_errors=yes setting
in v2.2 and just forcing it enabled always. Thoughts? (I didn't want to
change v2.1 behavior by doing this.)

The most important changes since v2.1.8:

	* mail-log plugin: Log mailbox names with UTF-8 everywhere 
	  (instead of mUTF-7 in some places and UTF-8 in other places)
	* director: Changed director_username_hash setting's default from %u
	  to %Lu (= lowercase usernames). This doesn't break any existing
	  installations, but might fix some of them.

	+ doveadm: Added "auth cache flush [<username>]" command.
	+ Implemented dict passdb/userdb
	+ Implemented Redis and memcached dict backends, which can be used as
	  auth backends. Redis can also be used as dict-quota backend.
	+ Added plugin { quota_ignore_save_errors=yes } setting to allow saving
	  a mail when quota lookup fails with temporary failure.
	- Full text search indexing might have failed for some messages,
	  always causing indexer-worker process to run out of memory.
	- fts-lucene: Fixed handling SEARCH HEADER FROM/TO/SUBJECT/CC/BCC when
	  the header wasn't lowercased.
	- fts-squat: Fixed crash when searching a virtual mailbox.
	- pop3: Fixed assert crash when doing UIDL on empty mailbox on some
	  setups. 
	- auth: GSSAPI RFC compliancy and error handling fixes.
	- Various fixes related to handling shared namespaces