* change g2rating,etc. to attr_reader (instead of attr_accessor) * move @dvolatility into DVOL constant * add p_win * make comparison operator use p_win(self,other) * use << when adding to results array instead of .push() * improved comments; mostly from Glicko2 document * minor variable renaming to improve readability * clear results array after ratings are finally updated (no functional change, just cleaner)