title: Two delayed jobs with same Timestamp.
body: <p>In Rails application if 2 or more <strong>delayed jobs</strong> are scheduled at the same run_at time eg: 24/1/2013 12:05:49 (exactly same timestamp). </p>
  
  <p>Then will only one of them will execute or both will execute irrespective of same run_at timestamp.?</p>