The Rev. Al Sharpton may claim he wore a wire for the feds because he had been threatened by the mob — but a new report says he turned rat to save himself after a federal drug sting. The FBI “flipped” the bombastic reverend after agents confronted him with a surveillance video showing him discussing cocaine with an undercover agent, The Smoking Gun Web site said Wednesday. During that March 1983 conversation, Sharpton wore a cowboy-like hat that was garish by even the rabble-rousing preacher’s 1980s standards. He later showed up at a Manhattan apartment for another meeting that June...