Right now, if the same rubric is attached to more than one assignment, and you edit the rubric in one assignment, it only changes the criteria for THAT assignment's rubrics, and creates a COPY of the previous version of the rubric, which is attached to the other assignments.  

We should be given the option when changing a rubric, whether we want these changes to apply only to this assignment (and thus duplicate the original rubric), or to make the same changes to all assignments that use this rubric.

We should also be able to update a rubric from the "Manage Rubrics" page, and have the updates apply to all assignments to which it's attached. This would save a lot of time, and ensure consistency across a course.