Fixed some logic errors in the DAL for user being the best scorer for
the "I Am the Greatest" achievement (wasn't taking into account
timeElapsed, and would also continue to award user "I Am the Greatest"
achievements even if they didn't beat their previous score). All
achievements now do not appear more than once in the newsfeed, unless
the user wins multiple "I Am the Greatest" achievements by beating their
previous score or beating someone else on a different quiz.