XTCE13 — RelativeTime's ChangePerSecondRangeAlarm should be a TimeChangesPerSecondAlarmType

RelativeTimeParamaterType static and change alarms are both TimeAlarmRangesType. At the very least it would be clearer if the ChangePerSecondRangeAlarm is its own type.
A simple solution would be to create a new type (TimeChangePerSecondRangeAlarmType) and have it extend TimeAlarmRangesType.
(Assuming that it's correct that both of these should describe alarms in the same using same underlying type.)