NEW YORK (Reuters) - Blind Chinese dissident Chen Guangcheng arrived in the United States on Saturday after China allowed him to leave a hospital in Beijing in a move that could signal the end of a diplomatic rift between the two countries. Chen's escape from house arrest in northeastern China last month and subsequent stay in the U.S. Embassy was a huge embarrassment for China and led to a diplomatic controversy while U.S. Secretary of State Hillary Clinton was visiting Beijing for talks to improve ties between the world's two biggest economies. ...