CHICAGO - It seemed like a good idea at the time. A gang of burglars decided in December 1977 to break into the home of Tony Accardo, one of the most powerful men in organized crime history, and rob his basement vault. Accardo was not amused. Six men Accardo blamed for the heist were swiftly hunted down and murdered, according to papers filed by federal prosecutors in preparation for Chicago's biggest mob trial in years, scheduled to begin Tuesday. And that's only one of the grisly tales jurors are likely to hear at the trial stemming from the FBI's "Operation...