THE HAGUE, Jan 28: Former Ivorian president Laurent Gbagbo Thursday pleaded "not guilty" to four charges of crimes against humanity as his landmark trial opened five years after post-election violence ravaged his nation. Gbagbo becomes the first ex-head of state to stand in the dock at the International Criminal Court (ICC) in The Hague, in a case which will test the tribunal's avowed aim to deliver justice to the victims of the world's worst crimes.     ?AFP