The fast-casual pioneer has generated robust growth for years. A stock split will make the shares much more affordable for the average investor.Chipotle (CMG 2.80%) has long been the standard bearer for the fast-casual dining it helped pioneer. The company's focus on fresh ingredients prepared daily has revolutionized the industry and made Chipotle one of the biggest successes in it. Over the past year, the stock is up an impressive 60% (as of this writing), and that's no fluke. Over the past decade, Chipot ...