Turning around its business in China is important to General Motors and its investors, and there's a little good news in that area.If you only started following or investing in the automotive industry in the past few years, it's probably difficult to believe that General Motors (GM +1.28%) once sold more vehicles in China than it did in its core profit engine, the United States. Despite climbing the mountain and becoming a major player in China, GM has suffered large setbacks as China's domestic automakers ...