Danny Gaido Cries In His Crib( All Photos: Esther Bubley, 1951)The Pittsburgh Photographic Library was founded to 1950 with a single mission: to document urban renewal in the Steel City. But its founding director, Roy Stryker, a Columbia University economist with a background in public relations, was also a photographer with an eye for undiscovered talent. This led to the hiring of photojournalists who could produce something more than business booster shots. A current exhibit at The Frick Art & Historical Center shows just how much more a great photographer can bring to the most ordinary assignment.Parents Visit Child In...