NEW ORLEANS, Jan 14 (Reuters) - On Martin Luther King Day last year, New Orleans Mayor Ray Nagin famously said his city would "be chocolate at the end of the day," a remark meant to encourage African Americans to return after Hurricane Katrina. At the time, it drew accusations of racial divisiveness and a barrage of jokes. T-shirts went on sale in the French Quarter portraying Nagin as Willie Wonka and maps of the city were redrawn with neighborhoods named Godiva, Hershey and M&Ms. But a year later, it is no laughing matter. New Orleans, one of the most culturally...