By Alister Bull WASHINGTON (Reuters) - The United States slapped financial sanctions on Thursday on a Greek businessman it says secretly operated a shipping network on behalf of the Iranian government to get around international sanctions on the country's sale of oil. "Today, we are lifting the veil on an intricate Iranian scheme that was designed to evade international oil sanctions," U.S. Treasury Undersecretary for Terrorism and Financial Intelligence David Cohen said in a statement. The U.S. ...