GENEVA — Top diplomats from the United States, European Union, Russia and Ukraine reached agreement after marathon talks today on immediate steps to ease the crisis in Ukraine. Reached after seven hours of negotiation, the agreement does not set out specific directions for Ukraine’s future, but it requires all sides to halt any violence, intimidation or provocative actions. It calls for the disarming of all illegally armed groups and for control of buildings seized by pro-Russian separatists to be turned …