Git commits in Moodle 3.3.5 by Davo Smith

commit 8566cace36ab12a4143c8b95d68121ed6125e429
Author: Davo Smith <davo.smith@synergy-learning.com>
Date:   Fri, 09 Feb 2018 19:53:41 +0800
Tag:    v3.3.5

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