FELIX ONUAH NIGERIA'S electoral commission began announcing state-by-state results from national elections, though it is not expected to name a victor in the race to succeed President Muhammadu Buhari for several days. The presidential vote is expected to be the closest in Nigeria's history, with candidates from two parties that have alternated power since the end of army rule in 1999 facing an unusually strong challenge from a minor party nominee popular among young voters. Votes in presidential and parliamentary elections are collated in each of Nigeria's 36 states before the count is transmitted to the electoral commission's central tallying centre in the capital…