This setting is not compatible with combinations of aggregation methods
and the ways in which it does and does not work are not documented. It
was voted to remove it completely by the gradebook workshop, so I have
completely removed it and added a warning for all affected courses + restored
backups.
While restoring course/activity, restore will blindly insert grade_item
sortorder. Which cause dulicate sortorder and lead to unpredicatble sorting
results.
Now we will call grade_item::fix_duplicate_sortorder() after restore is finished
to fix duplicate sortorder and order grade items to the closest order possible
This is a followup to MDL-18301. That fix missed the following points:
1. On the edit categories and items screens, all items had an eye-con to
control the visibility, even if the visibility was controlled by the
module.
2. Changing the visibility of a grade category change the visibility of
all items within it, even if the visibility was controlled by the
module.
3. The quiz ingored $cm->visible when controlling whether its grade item
was visible.
