Developer credits
Git commits in Moodle 3.1.1 by Mike Churchward
commit bbe5d6c8279bc9ad774cf86636caa934c21b2eaf Author: Mike Churchward <mike@remote-learner.net> Date: Thu, 02 Jun 2016 22:32:43 +0800 Tag: v3.1.1 MDL-54805 portfolio_download: Adding a 'require' of necessary library file