Don Sweeney has been criticized at times for taking too long to reach decisions over his two-season tenure as general manager of the Bruins.Not this time. Less than three days after the 2016-17 ended with Sunday’s 3-2, overtime loss to the Senators in Game 6 of a best-of-7 first-round playoff series, Sweeney got a jump on 2017-18 by naming Bruce Cassidy head coach.The announcement, made at 8 a.m.