By Daniel Kline The fast-food chain has a new philosophy when it comes to its classic menu items. McDonald’s (MCD) – Get McDonald’s Corporation Report has built its business on consistency, delivering the same experience at every restaurant. For roughly its first 25 years, that meant having a very simple menu that it executed well. Yes, it made changes and additions to the original hamburger, cheeseburger, fries, and drinks menu from the 1950s and 1960s. But additions like the Filet O’ Fish and the now iconic Big Mac were carefully planned. At first, that was because fast food was a slowly evo…