Supervisord needs a pid file for the process it needs to kill

[Venefyxatu]

Supervisor can't kill processes that fork and handle signals in the child - it needs to be told about the child's PID by means of a pid file.
This commit allows running phenny under supervisor.

See http://supervisord.org/subprocess.html#pidproxy-program for specific documentation.

[sbp]

Can you make this write to the directory of the config file instead?

You need to use the value from opts.config or the default.