[SpeedGrader] Grading functionality consistency

[PeterBransche]

It would be good to see consistency when using the speed grader or when editing grades for individual students.  One way allows adding attachments, editing comments, and deleting comments the other way does not.  I find myself having to switch between grading methods based on the task I need to accomplish.

Thank you.

Peter Bransché

[ezaurova]

Yes, please!