title: Update an existing JobDataMap
body: <p>I have a Quartz job that has already been scheduled.  I want to update the JobDataMap associated with it.  If I get a JobDataMap with <code>JobDataMap jobDataMap = scheduler.getJobDetail(....).getJobDataMap()</code>, is that map "live"?  ie. if I change it, will it be persisted in the scheduler?  If not, how do I persist it?</p>