A new health-oriented menu including gluten-free meatballs, low-calorie ranch dressing, and low-fat mozzarella cheese was unveiled by Boston Public Schools officials today and will be waiting for kids when they start school on Thursday.BPS inked a three-year, $38 million contract with California-based Revolution Foods, which will roll out the new school lunches beginning this fall.Revolution VP of Operations Neil Neufeld displaced samples of the meals this morning at a back-to-school press conference at the Perkins Elementary School in South Boston.