The Royale ***
By: Paulanne Simmons These days, when sports are so dominated by African-Americans, it's hard to picture a time when the world heavyweight boxing championship was off limits to a black boxer. The story of prizefighter Jack Johnson (now called Jack Jefferson), who first wrested the title from a white man in 1908, was most famously told in Howard Sackler's 1967 Tony- and Pulitzer-winning play, The Great White Hope, ada…