There has been a big vote of confidence from Warren Buffett (Trades, Portfolio)'s Berkshire Hathaway (NYSE:BRK.A)(NYSE:BRK.B), which has bought stock in the big airlines like American Airlines (NASDAQ:AAL), Delta Air Lines (NYSE:DAL), United Continental (NYSE:UAL) and Southwest (NYSE:LUV). Did Buffett make the trades? Considering the size, probably not. However, with the