[Dovecot] v2.1.2 released

[Timo Sirainen]

http://dovecot.org/releases/2.1/dovecot-2.1.2.tar.gz
http://dovecot.org/releases/2.1/dovecot-2.1.2.tar.gz.sig

There are a ton of proxying related improvements in this release. You
should now be able to do pretty much anything you want with Dovecot
proxy/director.

This release also includes the initial version of dsync-based
replication. I'm already successfully using it for @dovecot.fi mails,
but it still has some problems. See
http://dovecot.org/list/dovecot/2012-March/064243.html for some details
how to configure it.

	+ Initial implementation of dsync-based replication. For now this
	  should be used only on non-critical systems.
	+ Proxying: POP3 now supports sending remote IP+port from proxy to
	  backend server via Dovecot-specific XCLIENT extension.
	+ Proxying: proxy_maybe=yes with host=<hostname> (instead of IP)
	  works now properly.
	+ Proxying: Added auth_proxy_self setting
	+ Proxying: Added proxy_always extra field (see wiki docs)
	+ Added director_username_hash setting to specify what part of the
	  username is hashed. This can be used to implement per-domain
	  backends (which allows safely accessing shared mailboxes within
	  domain).
	+ Added a "session ID" string for imap/pop3 connections, available
	  in %{session} variable. The session ID passes through Dovecot
	  IMAP/POP3 proxying to backend server. The same session ID is can be
	  reused after a long time (currently a bit under 9 years). 
	+ passdb checkpassword: Support "credentials lookups" (for
	  non-plaintext auth and for lmtp_proxy lookups)
	+ fts: Added fts_index_timeout setting to abort search if indexing
	  hasn't finished by then (default is to wait forever). 
	- doveadm sync: If mailbox was expunged empty, messages may have
	  become back instead of also being expunged in the other side.
	- director: If user logged into two directors while near user
	  expiration, the directors might have redirected the user to two
	  different backends.
	- imap_id_* settings were ignored before login.
	- Several fixes to mailbox_list_index=yes
	- Previous v2.1.x didn't log all messages at shutdown.
	- mbox: Fixed accessing Dovecot v1.x mbox index files without errors.