The new Lockhart Smokehouse at Texas Live! is the third location for one of DFW’s top barbecue destinations. (Photo ©Michael Ainsworth/Texas BBQ Posse) The first time we wrote about Lockhart Smokehouse was in January 2011, before they opened their first restaurant in the Bishop Arts District of Oak Cliff. Their opening, along with that of Pecan Lodge in the Dallas Farmer’s Market, signaled a major change in the then-mediocre Dallas BBQ scene. The Posse joined in as Lockhart Smokehouse celebrated their first anniversary a year later, then we reported that great Texas barbecue had finally come to Plano when they opened their second location…