Git commits in Moodle 3.8.x by Martin Hanusch

commit 27a12aba40fc3e43920376fffc7c33f0c0759652
Author: Martin Hanusch <martin.hanusch@let.ethz.ch>
Date:   Tue, 02 Jun 2020 22:53:33 +0800
Tag:    v3.8.4

MDL-68772 mod_quiz: Navigation overlay fix

commit 6e64255df2038e016971d03952a5918afa5c406b
Author: Martin Hanusch <martin.hanusch@let.ethz.ch>
Date:   Fri, 29 May 2020 22:39:32 +0800
Tag:    v3.8.4

MDL-63284 question: Moving questions with tags disabled bug fix