Cheeseburgers are the unsung hero of many end-of-summer barbecues. If they’re your thing, save the date: Sept. 18 is National Cheeseburger Day.Eateries and fast food brands are serving up mouthwatering menu deals and discounts. Here’s the burger breakdown: Applebee’s: Get a Classic Burger or Classic Cheeseburger with fries for $8.99. Bad Daddy’s Burger Bar: Get the...