Cagney Opens @ York ****
New Musical about Hollywood's tough guy James Cagney in tap shoes! Robert Creighton: Photo: Barry Gordin      By: Patrick Christiano The New York premiere of Cagney, a highly entertaining new musical about the screen's greatest tough-guy, James Cagney, opened at the York Theatre, where the opening night audience was cheering uproariously after almost every musical number preformed by Broadway's Ro…