Hakim Glover, the cousin of the man who allegedly killed Officer Chuck Cassidy, pleaded guilty yesterday to charges of hindering apprehension and obstruction of justice. Glover is accused of helping his cousin flee to Florida. The Convention Center expansion project was halted on Christmas Eve when the Preservation Alliance of Greater Philadelphia obtained an injunction ordering wrecking crews to stop work. The preservationists want to save the two small but historic Broad Street buildings......