Issue generated from Tuleap's migration script. Originally submitted by: Guillaume Roguez (guillaume)
IM message are not delivered if the destination is not connected (normal situation),
but the daemon doesn't store it for later trial. So the message is only stored on the DHT until its TTL is over (5 minutes).
This ticket proposes to implement a way to store sent messages forever and retry to send them (period TBD),
until the user decide to flush them.