BY EDWARD J. BOYER FEB. 1, 1993 12 AM PT As the drawling, shuffling, dimwitted Lightnin’ on the “Amos ‘n’ Andy” television show in the early 1950s, Nick Stewart was part of a cast that officials at the NAACP’s national headquarters wanted taken off the air. But for Stewart, Lightnin’ was a means to an […]