E311/E011 Nonlinear Scoring of Teammate Reviews

the file model/questionaire.rb has a mistype which showed up as revised, please check that.
The db/migrate/115_create_score_caches.rb and db/migrate/126_update_cache.rb weren't changed also,
there are some comments in them.

The major calculation algorithm is done in model/scorecache.rb, and I changed the way final score is calculated in assignment_participant.rb to have the final score calculated when student hit the "view your score" button.