The drama over the Barnes Foundation’s future is about to get publicly nasty again. “A potentially explosive internal investigative audit of the Barnes’s finances in the 1990’s, long withheld by the foundation, was turned over late Friday to a judge, who may decide to make it public. And a new book, “Art Held Hostage,” published today by W. W. Norton, casts an unflattering light on machinations at the Barnes and its estranged partner, Lincoln University, that are drawing comparisons to the litigious mire of Dickens’s ‘Bleak House’.”