ARLINGTON, Va. — When it comes to movies, give me an adorable dog, a flawed father, a motherless girl-child with a heart the size of Disney World — toss in an eccentric dowager librarian and a Magical Negro (to borrow the term popularized by Spike Lee), not to mention Dave Matthews — and for two hours I'm all yours. Especially if I'm 7 years old. So goes the cast of characters in a new movie due for release Feb. 18 — "Because of Winn-Dixie" — that parents can take their children to without cringing. It's a sweet tale, full of...