This software has been produced by the CerCo project: http://cerco.cs.unibo.it. Copyright © 2010-2013 CerCo consortium. The software is released under the terms of the GNU/GPL license. The project CerCo acknowledges the financial support of the Future and Emerging Technologies (FET) programme within the Seventh Framework Programme for Research of the European Commission, under FET-Open grant number: 243881.