Log infohashes in hex
             Don't write out nodes if we don't have any

   - Remove static SnarkManager instance
   - Allow DHT-only torrents
   - DHT debugging

- Protect against null DHT races
- Add message about restarting tunnel when DHT config changes
- Add DHT size to table totals

This is required in order to get the theme config keys of the various apps into
themes.config; this way, the routerconsole requires no knowledge of what apps
support universal theming, and can just blanket apply themes to all known keys.

FIXME: ensure that _theme is only read from the config file once per page load.

Directory column could do with a different icon.

The header icons are self-explanatory (but tooltip also has header text); the
status text is available from the tooltip.

   - Don't send a keepalive to a peer we are going to disconnect
   - Disconnect peer when idle a long time
   - PeerCheckerTask cleanup
   - Static ref cleanup
   - Don't show a downloaded torrent file as "seeding"
   - Better torrent file download icon (from Silk, same license as the others)

- final infoHash in Snark