NEW YORK, July 11 (Reuters) - ByteDance, the Chinese owner of short video app TikTok, will allow shares of U.S. employees to vest without waiting for the company to list in the stock market, thereby allowing them to cash out, according to people familiar with the matter. The move is aimed at appeasing restless employees who have been waiting for an initial public offering to profit from the shares they have been awarded as part of their compensation. It is also an indication that ByteDance, whose worth in excess of $200 billion makes it the world's most valuable startup, is...