bug 882110, move push-poller and repo work into a10n, r=jezdez
This migrates the twisted hg poller from master-ball to a10n.
It also splits out the repository and elmo db work into a
single kombu worker.
The latter is started via the scripts/a10n runner script.
remove Django from vendor-local, use upstream 1.4.5 per requirements
bug 882110, fix some nits, argparse in requirements, don't catch KeyboardInterrupt