A few final touches on the Upstart job

(a) use static-network-up, since it is more generic than the started networking event
(b) do not hook into network deconfiguration to speed up shutdown
(c) expect fork, per the use of the "-f" option
(d) use a variable for the run directory to make changing it simpler
(e) handle the situation of a left over socket file
(f) use the -f option to be able to track the PID