[Dovecot] v2.2 status update: IMAP NOTIFY extension and more

v2.2 hg now has support for NOTIFY extension. The only thing missing is support for SubscriptionChange events. Now would be a good time for IMAP clients to start implementing and testing it. :) I remember K9 developers at least said they were just waiting for Dovecot to support it first.

v2.2 implements some other extensions also: BINARY, CATENATE and MOVE. Stephan has also implemented URLAUTH pretty far. Hopefully it gets finished in time for v2.2.0. I'll also try to implement the rest of the LEMONADE extensions: CONVERT, CONTEXT=SORT and URLAUTH=BINARY.

I'm also considering implementing an SMTP submission server, which works only as a proxy to the real SMTP server. The benefits of it would mainly be:

• It could support BURL command and other extensions required by LEMONADE. The real SMTP server would see only regular DATA commands.
• Would make SMTP AUTH easy to implement regardless of what the real SMTP server is.