By Fatos Bytyci and Yannis Behrakis GEVGELIJA, Macedonia, IDOMENI, Greece (Reuters) - Crowds of migrants and refugees were building on Greece's border with Macedonia on Saturday after a cold, wet night spent in the open, their entry slowly rationed by Macedonian police and soldiers. Most of them Syrian refugees, the crowd of several thousand shouted "Help us!" at lines of riot police behind razor wire, stationed on the border since Thursday when Macedonia declared a state of emergency and sealed the frontier. On Friday, Macedonian police fired tear gas and stun grenades to drive back angry crowds of Syrians, Afghans, Iraqis and others seeking passage through the impoverished Balkan country, the latest flashpoint in a crisis that has dragged the conflicts of the Middle East to Europe’s doorstep.