Woman is helped by officials as she votes in a referendum at a polling station in HarareBy using MacDonald Dzirutwe CHITUNGWIZA, Zimbabwe (Reuters) – Zimbabweans voted on Saturday in a referendum anticipated to advise a brand new constitution that might trim presidential powers and pave the best way for an election to come to a decision whether or not Robert Mugabe extends his three-decade rule. Mugabe, Africa's oldest president at 89, has dominated the previous British colony when you consider that independence in 1980 and has been accused of waging violent crackdowns on the opposition and weakening state institutions like the cabinet and parliament. …