BEIRUT (Reuters) - The Syrian army and allied forces have come to within three km (two miles) of a government-held enclave besieged by Islamic State in the city of Deir al-Zor, state television said on Monday.  With a lunge through jihadist lines, the army and its allies are close to relieving the Euphrates city, where Islamic State has surrounded an army garrison and 93,000 civilians for years. 