GitLab

We'd like to be able to refresh then _wait_ for the refresh to finish in the testground DHT tests. That way, we can:

1. Start and disable _auto_ refresh.
2. Bootstrap.
3. Refresh a couple of times till we're stable.
4. Wait to _stop_ refreshing.
5. Disconnect from and forget about all peers _not_ in our routing tables.
6. Run the actual tests without interference from the bootstrapping logic.