Adding dual stack IPv4 + IPv6 support to DHT.

Open to suggestions on how to improve the code or organize it better welcome.

It's working well for me.  Here's a run:
$ go run main6.go -v6 [2601:c:a200:1228:76d0:2bff:fe90:8b90] 12b9b08b325e877d08cc63a75e8fd24699c3dc6b
Tring to bind to IPv6=[2601:c:a200:1228:76d0:2bff:fe90:8b90]
=========================== DHT
Note that there are many bad nodes that reply to anything you ask.
Peers found:
=========================== DHT
Note that there are many bad nodes that reply to anything you ask.
Peers found:
0: [2505:20f6:19c2:2a:9c01:fe:00ca:dd11]:8445
0: 114.40.158.84:19944
1: 220.135.171.68:11183
2: 125.81.132.91:8978
3: 154.45.216.164:1073
4: 185.6.124.193:49572
1: [2601:c:a200:1228:76d0:2bff:fe90:8b90]:8445


Change back to nictuku.

Usually when working on go github projects, you should 'go get' the original project and then add your fork as an another remote. Then you can keep working on it without changing the import path.