Hong Kong sank on Friday on an otherwise mixed day for Asian markets, with Chinese ecommerce titan Alibaba Group Holding Ltd (????) tanking more than 10 percent after warning of a weaker outlook. Alibaba on Thursday said that net profit tumbled 81 percent in the second quarter and revenue grew less than forecast as it was hit by slowing economic growth and a government crackdown on the technology sector. The firm said income growth over the rest of the fiscal year fell short of expectations, adding that certain factors could further affect results including “changes in laws, regulations and [the]...