Queue cleanup

[Paul Rubin]

EW <ericwoodworth at gmail.com> writes:
> Well I cared because I thought garbage collection would only happen
> when the script ended - the entire script.  Since I plan on running
> this as a service it'll run for months at a time without ending.  So I
> thought I was going to have heaps of Queues hanging out in memory,
> unreferenced and unloved.  It seemed like bad practice so I wanted to
> get out ahead of it.

Even if GC worked that way it wouldn't matter, if you use just one queue
per type of task.  That number should be a small constant so the memory
consumption is small.