Git commits in Moodle 3.6.4 by Tim Hunt

commit ba61f2f91bc44caf9743d60afcba3d2f17afe594
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Mon, 15 Apr 2019 23:50:46 +0800
Tag:    v3.6.4

MDL-60418 Behat: Fix broken docs links in Behat code.


commit 991ecfec2874d963ba41f5079f2001586d68286b
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Mon, 08 Apr 2019 19:19:13 +0800
Tag:    v3.6.4

MDL-65296 questions:  field should be declared


commit 5b898cb5e0547f79444b3e0c6010ebd1383948cc
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Fri, 29 Mar 2019 21:24:53 +0800
Tag:    v3.6.4

MDL-65029 questions: refactor generation of question div id