The Quartz Scheduler interface has a shutdown(Boolean waitForJobsToComplete) method on it, but there is no way to exit the method if there are long running tasks. We need to implement a version with a timeout. Note that this would still leave the scheduler shutdown, but at least would allow us to restart it if required.

The method should call Scheduler.shutdown() and then check the result of Scheduler.getCurrentlyExecutingJobs() until it becomes empty.