Services API: Enable use of RecordedId with GetRecordSchedule to return the rule which created that recording and using the metadata associated with that recording.
WebFrontend: Tweak the behaviour of the schedule editor depending on whether it's called for an upcoming recording, an existing recording or a recording rule. This isn't exactly ideal, but I didn't want to change the behaviour of the Services API GetRecordSchedule to achieve what we want, at least not at this stage.