Expire contexts

[suchow]

When an experimenter runs a script and then stops it before completion, with no intent to ever run it again, future participants will claim any outstanding persons instantiated by the script before getting any new tasks from other scripts. It would be nice if we had a method to pause or freeze outstanding tasks when the experiment script is not running. At least, we should have a method by which an experiment can clean up a finished experiment so that it is not seen by future participants.