Who would have ever thought that McDonald's -- known throughout the world for its Happy Meals, iconic gold arches, and, of course, Ronald McDonald -- would be foundering in 2015? The fast-food giant's profit and sales have fallen off a cliff over the past year or so, prompting executives to make drastic changes in the way McDonald's does business. It's pretty easy to pin down why McDonald's finds itself in dire straits. For one, millennials are flocking to more healthful alternatives like Chipotle Mexican Grill, Chick-fil-A, and Five Guys. In light of the well-publicized obesity epidemic, concerned parents now frown upon McDonald's kid-targeted advertising. Even the company's drive-through service, which was humming along just a few years ago, is slower than ever. In an effort to break out of this sales slump, McDonald's is working on upgrading its menu and stores, improving service, and implementing modernized payment systems. They're even tes...