Redis sentinel support in dict

[Lazy]

Redis sentinel ( http://redis.io/topics/sentinel ) is a service that monitors
and manages redis master slave replication.

Using sentinel you can easily create a redis ha cluster. You can connect
to a sentiniel and subscribe to certain events then in case of an
failover update the redis address to new master etc.

I think this is better suited to be used with dict proxy.
Do You think it can be implemented without changes to dovecot core ?

-- 
Michal Grzedzicki