Oscar-winning screenwriter Diablo Cody is reunited with Oscar-winning actress Charlize Theron in "Tully," an offbeat comic drama about, of all things, postpartum depression. Theron plays a woman who delivers her third child. Because of exhaustion, she agrees to let her wealthy brother pay for a night nanny, played by Mackenzie Davis. The plot focuses on the relationship that develops between these two. Theron is excellent and the dialogue is often very sharp and funny, but the movie's main conceit and strange finale may be off-putting to many. Renowned violinist, conductor and teacher Itzhak Perlman is the focus of the documentary "Itzhak." It chronicles his journey from his impoverished youth in Israel, to his battle with polio, his immigration to the US at the age of 13 in 1958 and his rise to become one of the most celebrated classical musicians of our time. Fortunately, there's plenty of concert footage and early video available to accompany the filmmakers' peek into his life behind the scenes. It's a fitting tribute to a uniquely gifted individual. Also opening this week, "Overboard" is a remake of the classic 1987 Kurt Russell/Goldie Hawn comedy, but they've flipped the script this time by changing the gender…