ALGIERS, Algeria — The bloody three-day hostage standoff at a Sahara natural gas plant took a dramatic turn Friday as Algeria’s state news service reported that nearly 100 of the 132 foreign workers kidnapped by Islamic militants had been freed. That number of hostages at the remote desert facility was significantly higher than any previous report, and still meant that the fate of over 30 foreign energy workers was unclear. Yet it could indicate a potential breakthrough in the confrontation that began when the militants seized the plant early Wednesday. The militants, meanwhile, offered to trade two captive American workers …