Liveness Error information [gitlab]

[jmwample]

When a phantom is identified as live by PhantomIsLive() we should gather more information about how long it took to make a decision so that we can track if we are getting close to the timeout in a significant portion of liveness tests for a specific subnet.

This could also be a place to prevent registrations from getting added to stations that won't be able to service them.

• log time to decision for liveness tests
• If we receive more than one registration only scan liveness once (or twice)
• block registrations and liveness scans for subnets that can't be serviced from a given station.

original submission: 12/19/2019

[jmwample]

Time to decision will only be interesting if the host is not live. (though I believe that we did add this). This also related to issue #31