MANAMA, Dec 29 (Reuters) - A court in Bahrain sentenced two Shi'ite Muslim men to death and handed a third a life sentence on Monday after they were convicted of killing a policeman. The ruling could further destabilise the Western-allied kingdom, where sporadic protests have erupted and occasional bomb attacks have taken place since the government quelled mass protests in 2011 led by Shi'ite Muslims demanding reforms. ...