A couple allegedly squatting in a Bronx public housing complex abused and neglected their two young girls so severely that the starving youngsters were forced to eat their filthy foam mattress, prosecutors charged on Monday. The girls — three and four years old — were bruised, naked and covered in feces when cops and city workers finally rescued them May 3 from a “house of horrors” at NYCHA’s Mitchel Houses, the Bronx District Attorney’s Office said. Now, their mom Stephanie Grabowski and her beau, Mark Russell, have been indicted on a slew of criminal charges, including kidnapping, unlawful imprisonment and...