MDL-10392 updated links to edit_grade form, corrected the loop for table rows, which...

MDL-10392 updated links to edit_grade form, corrected the loop for table rows, which only initialised the $element object at the end of the loop
MDL-10211  Removed showfeedback preference
MDL-10286 Changed tooltip so that it surrounds the grade in a span when edit mode is off, and surrounds the edit icon otherwise
MDL-10287 Deleted edit_feedback and edit_feedback files and links to this form
MDL-10368 Removed show/hide feedback toggle