Author Robb Walsh doesn’t think much of the best-of barbecue lists compiled by bloggers and journalists. But we won’t hold that against him.  The former food writer at the Houston Press, whose Barbecue  Crossroads was just issued by the University of Texas Press, admits he was once there himself. Besides, Crossroads is a fine book. As a barbecue road trip account, it’s everything that Daniel Vaughn’s The Prophets of Smoked Meat isn’t. “Take off your jacket, honey, make yourself comfortable,” Thelma Williams of Thelma’s in Houston tells a New York companion of Walsh’s during their visit to her place. Thelma…