On the acknowledgment page to his new novel, “The Nickel Boys,” Colson Whitehead writes that in the summer of 2004, he learned about a 111-year-old reform school in Marianna, Florida – the Dozier School for Boys. It had been the subject of a recent Tampa Bay Times report, following discoveries by students at the University of South Florida of secret gravesites at the school. Further investigation turned up testimony of extensive physical, mental and sexual abuse, and flagrant corruption by