Hundreds of thousands of Chinese tourists visit the United States each year, but fewer than 50,000 went to its southern neighbour Mexico last year. But Mexico's looking to change that.   Its tourism secretary Claudia Ruiz Massieu has been visiting Hong Kong and the mainland to woo Chinese investors and tourists.   She said that last year Mexico saw about 1,500 Hong Kong visitors and around 47,000 from the mainland. "We're looking to grow those flows" she added at the start ...