Top EU leaders on Sunday presided over an inaugural ceremony for the Conference on the Future of Europe, kicking off a much-ballyhooed, yearlong, gabfest on the trajectory of the European Union that may, or may not, lead to revisions of the Union’s organizing treaties. The inaugural event, held symbolically on Europe Day, in the hemicycle of the European Parliament in Strasbourg, was titled “The Future is In Your Hands” — a reference to leaders’ hopes that the conference will gather the views and opinions of European citizens.