PARIS (Reuters) - French President Francois Hollande will set out his vision of the European Union's future in a keynote address to the European Parliament next week, his office said on Monday. The "solemn" speech, followed by a debate with the leaders of the political groups in the Strasbourg-based EU legislature, gives the Socialist leader a chance to respond to British Prime Minister David Cameron's call for a reformed EU that returns more power to member states. ...