Sir Ian Dunham interviews the novelist Allan Gurganus about his new book, “Local Souls.” Dunham: Your just-published collection of novellas, “Local Souls,” has been compared to John Cheever’s randiest suburbia, to Humbert Humbert’s bedtime stories for an underage “Lolita,” and to Grace Metalious’s 1956 popular novel of village erotics, “Peyton Place.” In a review in the Times, Dwight Garner gave t