LAGOS, Nigeria (AP) ? The film stars an Oscar nominee, is set in Nigeria during a civil war, is based on an award-winning novel and the head of Nigeria#39;s censorship board reportedly loved it. Yet a week after the scheduled premiere of quot;Half of a Yellow Sun,quot; it still has not been shown in any theater in Nigeria. Many commentators on social media believe that the censors are afraid that tribal rivalries could be inflamed if the movie is shown in theaters across Africa#39;s most populous nation. Nigerian government censors are effectively banning the film but they will not say why, the film#39;s director, Biyi Bandele, told The Associated Press on Thursday. He spoke in a...