HANGZHOU China (Reuters) - E-commerce giant Alibaba Group Holding Ltd reported more than $9 billion in sales on China's Singles' Day on Tuesday, illustrating the buying power of the Chinese consumer and the importance of the event in the retail calendar. Real-time figures on a giant screen at Alibaba's sprawling Hangzhou campus surged past 2013's record to 57.1 billion yuan ($9.3 billion) just after midnight after Chinese and overseas shoppers snapped up heavily discounted goods online. The shopping day, similar to Cyber Monday and Black Friday in the United States, comes less than eight weeks after Alibaba's record $25 billion...