fixed loadMixevaldetails in evaluation component

Fixed the undefined User object which is needed for the
getEventGroupMembersNoTutors function that was used.
implemented the basic and detail modes for student simple eval results
modified events add, edit, view

I've included the option to set the students result mode to be
detailed or basic in the events add and edit page. I've also
included the field in the events view.
implemented students' basic view of rubric results
modified mixeval evaluation form for students

It now looks like mixeval view for instructors
implemented working form for mixed evaluation (peer to peer).
implemented working mixeval form for students

However needs some code clean up.
removed unused code from mixeval form and fixed some related tests