Run "servers" as supervisor process groups.

[danielballan]

Per discussion with @DanOlds and @mrakitin:

PDF runs these xpd[Acq?View?Something?] "servers" that consume from 0MQ and do things. They should run as supervisor services so they can be more easily monitored, restarted in bulk, etc.

The supervisord in question should be probably be run as xf28id1 so that beamline users can restart these services when they consume too much memory or need to be reconfigured.