Ora2/hotfix 8 5 2014

This hotfix resolves two issues.

First, it will prevent erroneous rendering in the grading section, second, it will avoid an unnecessary additional call to render the peer assessment section, which could cause one student to assess the same student twice. 

This is the minimal approach to resolve the "double assessment" issue. Additional work will follow to allow the API to be more resilient when two requests for peer assessment occur at the same time. 

@wedaly @gradyward

cc:  @jimabramson