A former Barneys executive has sued a scion of the fallen luxury empire over his bestselling memoir , claiming the book falsely blamed him for the iconic retailer’s downfall — and that the author and his brother were the real culprits. Ex-Barneys president Charles Bunstine alleges that Gene Pressman’s “They All Came to Barneys: A Personal History of the World’s Greatest Store” is a smear to his reputation — with the book falsely claiming that Bunstine “had neither the feeling, nor the