BEIJING (Reuters) - Chinese Communist Party chief Hu Jintao has vowed to "purify" the Internet, state media reported on Wednesday, describing a top-level meeting that discussed ways to master the country's sprawling, unruly online population. Hu made the comments as the ruling party's Politburo -- its 24-member leading council -- was studying China's Internet, which claimed 137 million registered users at the end of 2006. Hu, a strait-laced communist with little sympathy for cultural relaxation, did not directly mention censorship. But he made it clear that the Communist Party was looking to ensure it keeps control of China's Internet users,...