By Colette Bennett McDonald’s carefully treads between innovation and the classic comfort food its customers come back for time and again. While some fast-food fans are all about trying the newest, weirdest thing at their chains of choice, others prefer the classics. McDonald’s (MCD) – Get McDonald’s Corporation Report knows this, and it carefully treads between innovation and the classic comfort food its customers come back for time and again. Thanks to its prominence and market share, the chain can afford to take chances its competitors can’t. But it prefers to make small moves within its es…