Commenting on a brawl that resulted in the ejection of more than 200 fans from the Colby-Bowdoin hockey game December 3 at Alfond Arena, the Echo chastised students who instigated the fight.      "Picking fights with Bowdoin fans proves nothing and reflects poorly on the entire student body," the Echo said in an editorial. "Other schools have banned students from hockey games between rivals because of excessive violence and inappropriate behavior. How far are we willing to push before we are no longer allowed to watch our team engage in one of the longest-standing rivalries in NESCAC?"     The incident occurred midway through the second period when a group of Colby students entered the Bowdoin cheering section and began taunting the fans. A fight broke out and police, unable to identify all of the individuals involved, cleared the entire seating section. Only a handful of spectators actually were involved in the fight, according to Waterville police. Five students, including one from Colby, were arrested.     Colby won the game, 3-2, in overtime.