By RAY KELLY Herman J. Mankiewicz co-wrote Citizen Kane and his kid brother, Joseph L. Mankiewicz, scripted and directed All About Eve — not too shabby for the sons of a school teacher and seamstress who left Germany for the United States shortly before the start of the 20th century. Sydney Ladensohn Stern — author … Continue reading ‘Brothers Mankiewicz’ looks at achievements, relationship of Hollywood siblings