Merge lp://qastaging/~clint-fewbar/ubuntu/lucid/squid/fix-upgrades-after-reload into lp://qastaging/ubuntu/lucid/squid

This branch fixes the problem by checking to see if the problem the recent update is trying to correct has actually happened, and if so, doing a stop/start on the service using invoke-rc.d Between the stop/start, it also kills the errant pid (but only if invoke-rc.d worked, so policy is still respected).

I test this on a lucid vm in the following scenarios:

* bare bones no updates with just 'apt-get install squid' version 2.7.STABLE7-1ubuntu12
 - When preinst is run, the upstart pid and the pidfile agree, and so it exits doing nothing.

* same, but also running 'sudo reload squid', verifying that squid is not tracked by upstart anymore with 'status squid' showing stop/waiting, but 'ps auxw | grep squid' showing a running squid.
 - the job is stopped, the old squid is killed, squid is started again

* start squid, reload, kill -9, leaving stale pid file.
 - Code stops because /proc/`cat pidfile` does not exist.

* modify /etc/init/squid.conf to not use expect fork, and pass -N (basically manually putting in the new job file). This simulates the chance that a user may have applied the fix manually.
 - Code stops because the upstart pid matches the pidfile.

* stopped service before hand
 - pidfile is gone, code is not run

* removed upstart file
 - code checks for that, does not run.