added add_contest_column() upgrade to add Contest.is_scoring_completed
removed add_sponsor() moved to manage.py
made add_sponsor() callable from command line
added Contest.is_scoring_completed default
if the contest has expired and scoring is completed, allow the
contestant to view their scores using the "My Score" nav item
only show social links for active contests
added Contest.is_scoring_completed column
added optional task parameter to user_submission_url()
don't render Donate form for expired contests
don't show social links for expired contests