Change wording of license statement
This MR changes the wording of the license statement at the top of every file. It also updates the license checker to enforce the new wording:
- // Copyright (C) 2016-2018 Acts project team
+ // Copyright (C) 2016-2018 CERN for the benefit of the Acts project
This currently is rebased on !572 (merged), but on top of it it ONLY changes these license statements, and the script, nothing else.