Adding information about restarting delayed jobs

This is information I believe is correct, but I would love to know for certain
Merge branch 'patch-1' of https://github.com/allenhancock/delayed_job into allenhancock-patch-1

* 'patch-1' of https://github.com/allenhancock/delayed_job:
  Adding information about restarting delayed jobs
Update documentation on restarting DJ