Work supported in part by ASI/INAF agreement n. 2014-024-R.1 and by PRIN–INAF 2014 “Probing the AGN/galaxy co-evolution through ultra-deep and ultra-high resolution radio surveys”. JGN acknowledges financial support from the Spanish MINECO for a “Ramon y Cajal” fellowship (RYC-2013-13256) and the I+D 2015 project AYA2015-65887-P (MINECO/FEDER). CH-M acknowledges the financial support of the Spanish MINECO through I+D project AYA-2015-66211-C2-2-P. MB is supported by the Netherlands Organization for Scientific Research, NWO, through grant number 614.001.451, and by the Polish National Science Centre under contract UMO-2012/07/D/ST9/02785. CJM is supported by an FCT Research Professorship, contract reference IF/00064/2012, funded by FCT/MCTES (Portugal) and POPH/FSE (EC). GR acknowledges support from the National Research Foundation of Korea (NRF) through NRF-SGER 2014055950 funded by the Korean Ministry of Education, Science and Technology (MoEST), and from the faculty research fund of Sejong University in 2016.