Include GeoIP database identifier in extra-info descriptors
With the recent change from ip-to-country to free Maxmind, relays can report very different country statistics in their extra-info descriptors. While it's possible to guess which GeoIP database was used from the running Tor version, operators can manually override the default GeoIP database and use their own database. Relays should include a unique identifier of the used database, which can be the shasum of the geoip file.