LOS ANGELES (Reuters) - Making his much-anticipated comeback as Oscar host after an eight-year absence, comedian Billy Crystal poked fun on Sunday night at his own reluctance to return as he paid light-hearted tribute to leading nominees for the 84th annual Academy Awards. In his ninth appearance as Oscar master of ceremonies, Crystal, 63, opened the show with one of his signature film montages, inserting himself into footage from the biggest and most-honored movies of 2011. ...