(Reuters) - Madonna says it's pretty obvious why she was drawn to the story of Wallis Simpson -- the American divorcee who was vilified for persuading a British king to give up his throne in order to marry her. The sometimes prickly pop superstar said she had been fascinated for years by Simpson before deciding to write and direct her second film, "W.E", which opens widely in U.S. movie theaters on Friday. The movie chronicles the romance and 1930s marriage of King Edward VIII and Simpson, who were shunned by British society after Edward renounced the throne to be with her. ...