VIENNA, **v 19 (Reuters) - Senior Muslim, Christian and Jewish leaders condemned violence by jihadi militants such as Islamic State (IS) at a Saudi-backed conference on Wednesday in a rare display of inter-faith unity aimed at promoting tolerance and diversity. Islamic State has caused international alarm by capturing large expanses of Iraq and Syria, declaring a Sunni "caliphate" straddling their borders and massacring those they deem apostates and infidel, like Shi'ite Muslims and Christians. ...