Born Volodymyr Ivanovich Leventon at Yalta, the film producer Val Lewton (1904-51) had many accomplishments to brag about and some that were kept on the downlow. As a 20-something writer, he penned a notorious erotic pulp novel, “Grushenka: Three Times a Woman.” As a 30-something producer at MGM, Lewton purportedly advised his boss, David O. Selznick, that it was impossible to adapt Margaret Mitchell’s novel, “Gone With the Wind,” for the movies — that Selznick, in so many words, should forget about it.