Before Julia Child was a famous cookbook author, before she became television's first iconic television chef, and long before she was played by Meryl Streep in the Nora Ephron film "Julie and Julia," Julia Child worked for the Office of Strategic Services, or OSS. The OSS was a spy organization formed during World War II and was a predecessor to the CIA. Julia met Paul Child while they both served in the OSS in the 1940s.    Jennet Conant  takes a closer look at that time in their lives in her new book,  "A Covert Affair: Julia Child and Paul Child in the OSS."