Airport news: SFO Centurion crowd control + Dallas + LAX + ATL + Heathrow

In airport news, American Express tightens access to its Centurion Lounge at San Francisco International; AmEx opens an expanded lounge at Dallas/Ft. Worth; security screening is relocated at Delta's Terminal 3 in LAX; Atlanta debuts a popular new burger joint; and British Airways makes connections easier at London Heathrow.