dht find connected peers

This PR extends the DHT to send information re: peer "connectedness".
This means that --upon resolving dht queries -- connected peers will
signal whether or not they are directly connected to the peer. this is
in preparation for mesh messaging, and our "STUN" for NAT traversal.
> this is a separate issue, and yes, if that's used incorrectly it's pretty bad. In servers though, logging the error often IS exactly what we want to do (think 404s, 500s, etc)

I mean to call attention to the fact the this separate issue is the actual reason why one would begin to lose confidence in errors.