- Try to pick better introducers by checking shitlist,
        wasUnreachable list, failing list, and idle times
      - To keep introducer connections up and valid,
        periodically send a "ping" (a data packet with no data and no acks)
        to everybody that has been an introducer in the last two hours
      - Add a stat udp.receiveRelayRequestBadTag, make udp.receiveRelayRequest only for good ones
      - Remove some 60s and 5m stats, leave only the 10m ones
      - Narrow the range for the retransmit time after an allocation fail
      - Adjust some logging