* Britain's Froome wins Tour de France * Becomes second successive British Tour champion * Marcel Kittel of Germany takes Champs Elysees sprint (Writes through) By Julien Pretot PARIS, July 21 (Reuters) - Chris Froome crossed the Champs Elysees finish line arm in arm with his beaming team mates on Sunday to win the 100th Tour de France and hand Britain a second successive triumph in cycling's biggest race. ... More...