Need a way to count fraction of upgraded Guard nodes/capacity
Part of 0.2.2.34 was a feature for directory authorities to take the Guard flag away from relays that haven't upgraded to 0.2.0.31 or 0.2.2.34 or 0.2.3.6-alpha, so they can't be used to probe for presence of users who haven't upgraded.
We turned the feature off manually in some of the directory authorities, until enough Guards have upgraded that we won't cripple the network.
We need to look at what fraction of guards have upgraded, and what fraction of capacity that represents. Once we see what the upgrade trend looks like we can decide when we should flip the switch and take away the flag from the unpatched relays.