In 1990, William Deresiewicz was on his way to gaining a Ph.D. in English literature at Columbia University. Describing that time in the opening pages of his sharp, endearingly self-effacing new book, “A Jane Austen Education,” Deresiewicz explains that he faced one crucial obstacle. He loathed not just Jane Austen but the entire gang of 19th-century British novelists: Hardy, Dickens, Eliot . . . the lot.