ANGE ABOA and AARON ROSS AS sleek highway overpasses and shopping malls sprouted in Ivory Coast's commercial capital Abidjan following the 2010-11 civil war, investors often pointed to 2020 as the year that could unleash the country's full economic potential. A successful transfer of power when President Alassane Ouattara's second term expired, they said, would help banish memories of the disputed 2010 election that led to the war and attract other investors still wary about instability. But as Ivory Coast heads toward an election on Saturday that Ouattara is unexpectedly contesting and his main opponents are trying to sabotage, that…