the right information for peer grading

the beginnings of peer grading.

Vik/modify rubric input

Make things more robust, ensure that a rubric is specified properly before combined open ended module will render

related to rubric rendering. Remove the old input type.

Conflicts:
	common/lib/capa/capa/inputtypes.py

Clean up capa by removing message post actions that aren't needed

Feature/vik/integrate sa and oe

Fix/vik/staff grading settings

to handle rubric input

and set up the new rubric