Git commits in Moodle 3.8.x by Claude Vervoort

commit 6d79bed31b54a6b049678b07f8111de7958ec4b3
Author: Claude Vervoort <claude.vervoort@cengage.com>
Date:   Fri, 02 Oct 2020 03:12:15 +0800
Tag:    v3.8.6

MDL-57756 mod_lti: params change to text type

commit d2c96c5be95618182aa396b0762a0f27f4f86dcf
Author: Claude Vervoort <claude.vervoort@cengage.com>
Date:   Fri, 14 Feb 2020 04:19:48 +0800
Tag:    v3.8.2

MDL-67132 mod_lti: document new param

commit 1fde9dea678a6441958334a7f27705d58d500b83
Author: Claude Vervoort <claude.vervoort@cengage.com>
Date:   Wed, 06 Nov 2019 00:09:51 +0800
Tag:    v3.8.2

MDL-67132 mod_lti: call grade api to trigger course total computation

commit fbd182959416f1626e38218f4d78ed142494c0e5
Author: Claude Vervoort <claude.vervoort@cengage.com>
Date:   Thu, 24 Oct 2019 22:49:47 +0800
Tag:    v3.8.1

MDL-66708 lti adv: fix check for key in config