First published in 1961, Lorenza Mazzetti’s “The Sky is Falling” (“Il cielo cade”) is an impressionistic, idiosyncratic, and uniquely funny look at the writer’s childhood after she and her sister are sent to live with their Jewish relatives following the death of their parents. Bright and bucolic, vivid and mournful, and brimming with saints, martyrdom, ideals, wrong-doing and self-imposed torments,