Git commits in Moodle 3.3.x by Marcus Fabriczy

commit a83ceb2be84f6ff97ed819678a8be53e3a1c0034
Author: Marcus Fabriczy <marcus.fabriczy@blackboard.com>
Date:   Tue, 03 Apr 2018 11:14:16 +0800
Tag:    v3.3.6

MDL-60196 core_course: Fix the display of custom LTI icons

commit 78c66df3e55d2250bd1b7d82458577ea02b698af
Author: Marcus Fabriczy <marcus.fabriczy@blackboard.com>
Date:   Sun, 10 Dec 2017 11:16:25 +0800
Tag:    v3.3.4

MDL-59709 mod_assign: Export to portfolio button not working

commit ad95dcaccb887c1fd7b3ffd1e9e3f6593e041a08
Author: Marcus Fabriczy <marcus.fabriczy@blackboard.com>
Date:   Tue, 14 Nov 2017 19:42:41 +0800
Tag:    v3.3.4

MDL-60546 mod_choice: Fixed select all functionality