Take the Tor exit list from Onionoo, which has the IPv6 exits (closes #234)

check.torproject.org lists IPv4 exits only, so is_tor was false for an IPv6
exit. tor_exits now comes from Onionoo's details document, read by a new
format that takes every address in exit_addresses and or_addresses.

Model: opus-5-5

README.md

@@ -424,8 +424,9 @@ The lists:
   leased by spammers or cyber criminals, according to Spamhaus. From
   [Spamhaus DROP](https://www.spamhaus.org/blocklists/do-not-route-or-peer/),
   downloaded once a day.
-- `tor_exits`: Tor exit nodes, where traffic from the Tor network leaves. From
-  the [Tor Project](https://check.torproject.org/torbulkexitlist), downloaded
+- `tor_exits`: the IPv4 and IPv6 addresses of Tor exit nodes, where traffic from
+  the Tor network leaves. From the Tor Project's
+  [Onionoo](https://metrics.torproject.org/onionoo.html) service, downloaded
   every hour.
 
 No list is downloaded more often than its publisher updates it or allows. Each