By Arshad Mohammed and Parisa Hafezi (Reuters) -Siamak Namazi, an Iranian American imprisoned in Iran for nearly seven years on espionage-related charges rejected by Washington as baseless, has been allowed out of Tehran’s Evin prison on a one-week furlough, his lawyer said on Saturday. Separately, his father and former United Nations official Baquer Namazi, who was also convicted on charges of “collaboration with a hostile government,” has been allowed to leave Iran for medical treatment, U.N. spokesman Stephane Dujarric said in a statement. It was unclear if the moves might be a step toward …