Invalidating a graded submission #1479
Description
There are a number of use cases where a graded submission might be invalidated
- Grading result is wrong
- Test submission
- Other reasons for not accepting a submission etc.
It would be useful if the staff could mark a submission as invalidated, leaving the submission and grading information as-is, but marking that it should not be used for point sums, statistics, etc.
This is a small change to the submission model