Automatically reconnect to the Tor control port

[DonnchaC]

OnionBalance needs to talk to the Tor control port to keep fetching and publishing descriptors. If the Tor control port connection goes away (e.g. for a Tor update and restart) then the OnionBalance daemon fails hard and does not try to reconnect. OnionBalance should retry and reconnect to the Tor control port when it becomes available again.

This limitation is affecting production users and has resulted in service downtime. It's a priority and should be fixed soon.