Added ability of managers and observers to see the authors of comments.
Added ways to view tasks and comparisons.  The quality of the information needs improving, but at least it's there.
Greatly improved the diagnostic tools.
Removed spurious file.
Made the 0-2000 grade unreadable, to prevent students reading too much into it.
Improved formatting of numbers.
Made the menus more rational.
editing reviews is tested
Merge remote-tracking branch 'origin/luca' into mshavlov