This allows users to have an easy way to enable control sockets for Tor. Turning it on does so via a unix domain socket. Intentionally I did not add the localhost+port path because I feel unsure about the safety of that, and nobodey has yet demonstrated a need. I suppose another nice option might be to let the user specify a specific path, but we didn't allow that for the socks-sock, so I was too lazy to allow it here either.