Voters in the  Republic of Congo are choosing a new leader on Sunday , with the incumbent, President Dennis Sassou N'Guesso, expected to win again after more than four decades in power in the oil-rich central African country. Three million people from a population of 5.7 million are registered to vote in the election, which pits Sassou N'Guesso against six other candidates, none of whom is seen as having a realistic chance of winning the top job. Two other major parties are boycotting the