Git commits in Moodle 3.4.2 by Davo Smith

commit e2bb36513fb13ae162d50b24a3b50748f4bb0570
Author: Davo Smith <davo.smith@synergy-learning.com>
Date:   Fri, 09 Feb 2018 19:53:41 +0800
Tag:    v3.4.2

MDL-61324 enrol_lti: fix detection of changed grades during sync