Eric Kayne, Houston Chronicle/The Associated PressIn this file photo, the seatbacks on Boeing’s 787 Dreamliner. After decades of red ink, U.S. airlines have gotten their financial houses in significantly better order. And while this new wherewithal certainly won’t mean more legroom or free checked bags, some carriers are exploring inexpensive ways to make flying economy class a smidge less arduous. Free meals and booze are returning on some long domestic flights, and gratis snacks are common again.