This version removes the peer DBM present in earlier releases. It is not necessary for regular clients and has been a source of problems. There is a long-term identity cache that can be enabled by making a directory called "iddb.d" in the home folder and restarting ZT1. This is probably something only our supernodes would need, since regular nodes can easily WHOIS peers they've forgotten about. On shutdown, the peer database is dumped to disk. It's then restored on startup. Peers that have not been used in a while are cleaned out, so this keeps this data set small. A DBM may re-appear later if it's needed, but for now it was YAGNI.