Karen Russell, author of the wave-making debut novel “Swamplandia!,” was on New York Magazine’s 2005 list of 27 impressive New Yorkers under the age of 26. In 2009 she received a 5 Under 35 award from the National Book Foundation. Last year she wound up on The New Yorker’s 20 Under 40 list. Nice numbers. But cut to the chase: Ms. Russell is one in a million. The proof id in "Swamplandia!"