Refactored get oncall responder. Has one method for name and another for
the full object. Also, put get oncall manager/supervisor functionality
into its own methods.
Redesigned the NPML Action element's interaction with the Action
service. Actions are now kicked off asynchronously. Action elements
gained a 'function' property which basically provides a way to pass an
argument to the action. Action state is stored within the Notification
and is passed to the action service with each call to a particular
action along with the current data for the Notification.