In a moment of inspired American innovation, Josh Springer sat at a restaurant in 2009 and was struck with an idea that could one day be recounted in the Smithsonian. (Or at least be toasted by grateful sports fans). Springer may forever end the dreaded stadium beer line. “If I can be the person that does that, I’ll die happy,” Springer, 28, joked Tuesday. Springer and his Montesano, Wash., start-up company GrinOn Industries have invented the “Bottom’s Up Draft Beer Dispensing System.”