Authors would like to acknowledge the support of the
following European Union projects: RIPLECS (517836-
LLP-1-2011-1-ES-ERASMUS-ESMO), PAC (517742-LLP-
1-2011-1-BG-ERASMUS-ECUE), EMTM (2011-1-PL1-
LEO05-19883), MUREE (530332-TEMPUS-1-2012-1-JOTEMPUS-JPCR),
and Go-Lab (FP7-ICT-2011-8/317601).
Furthermore, we also thank Spanish Ministry of Science and
Innovation for the Project TIN2008-06083-C03/TSI, and the
Community of Madrid for the support of E-Madrid Network
of Excellence (S2009/TIC-1650).