VENICE, Sept 6 (Reuters) - Award-winning director Ava DuVernay on Wednesday became the first African American woman to present a movie in competition at the Venice Film Festival, overcoming sceptics who had tried to talk her out of applying. "As Black film makers we are told people who love films in other parts of the world do not care about our stories," DuVernay told reporters ahead of the screening of her powerful, thought-provoking movie "Origin". "I can't tell you how many times I have been told: 'Don't apply for Venice, you won't get in'. And this year it happened. Thank...