ADDED: README with instructions how to test IterativeFindNode. Commands ifn,
      setid
  UPDATED: Each instance is assigned a random port to listen on for debugging
  purposes. Ping now calls shortlist if pong is received
  FIXED: IterativeFindNode checks size of shortlist before indexing. Bug in Update, case
  InBucket.
  TODO: shortlist is getting written over after response returns