Iraqis welcome U.S. Marines in Shatra By Sean Maguire SHATRA, Iraq, March 31 (Reuters) - Hundreds of Iraqis shouting "Welcome to Iraq" greeted U.S. Marines who entered the town of Shatra on Monday after storming it with planes, tanks and helicopter gunships. A foot patrol picked its way through the small southern town, 35 km (20 miles) north of the city of Nassiriya, after being beckoned in by a crowd of people. "There's no problem here. We are happy to see Americans," one young man shouted. The welcome was a tonic for soldiers who have not always received the warm...