What's the status of the 'old' DHT?

[JustinDrake]

In dht.go there seems to be two DHT protocols in use:

var ProtocolDHT protocol.ID = "/ipfs/kad/1.0.0"
var ProtocolDHTOld protocol.ID = "/ipfs/dht"

Are they both in use? If so are they being used in parallel, and when is the old one going to be deprecated?

[Kubuxu]

The old one is already deprecated, we initiate connections with the new one and if that fails we fall back to the old one.

[anacrolix]

See #320.