* Moscow championships to have triple protection * Sochi will not change security arrangements (Adds Sochi details) By Gennady Fyodorov MOSCOW, April 16 (Reuters) - Russian authorities have promised tougher security measures at August's world athletics championships after explosions near the finish line of the Boston marathon killed three people and wounded more than 100. "The security arrangements will certainly be reviewed after what happened in Boston," Russia's athletics chief Valentin Balakhnichyov told Reuters on Tuesday. ... More...