A teacher should be able to override the quiz close date in a relative dates course for a student.
- The override should not affect any other students
- If a student's quiz close date is overridden, the student should only be able to attempt the quiz before the override date.
- The override form should show the relative quiz close date for that user
- The 'Revert to quiz defaults' button should the reset "Close the quiz" field to the current student's relative quiz close date.