Git commits in Moodle 3.6.3 by Andreas Wagner

commit 1f7b1ad0f28860c0f6bc6dfac51df9887e2ebfdc
Author: Andreas Wagner <awagner@gmx.de>
Date:   Sun, 18 Nov 2018 23:34:05 +0800
Tag:    v3.6.3

MDL-60972 core_course: delete section files, when section is deleted.