Rebecca Davis editorAs soon as Chinese film fanatic Li heard the news earlier this month that the Cannes Film Festival had scheduled a surprise special screening for a documentary about political unrest in Hong Kong, he rushed straight to his computer to open the page for his favorite online bookstore.He already owned a copy of festival director Thierry Fremaux’s book, “Selection officielle,” but he didn’t want to miss the chance to order two more, fearing they could soon be taken off the