Git commits in Moodle 3.5.2 by Tim Hunt

commit be092b730910ad97fff0511e177a097ec1cc4b1c
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 10 Jul 2018 01:37:45 +0800
Tag:    v3.5.2

MDL-62880 qtype_ddwtos: drop support for legacy import format

commit 8cc2d39207923a524881e45486e9fcd0d40ae199
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Thu, 05 Jul 2018 23:59:45 +0800
Tag:    v3.5.2

MDL-62811 question bank: rendering shouldn't load individual questions

commit e088a1f198535dc0d5ebbc70b6770fe80388628c
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Fri, 22 Jun 2018 17:45:56 +0800
Tag:    v3.5.2

MDL-62781 question/privacy: fix tests with CodeRunner is installed

commit 12d4fe9ee62e91a956e20acb99279adefb93ff01
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Thu, 21 Jun 2018 19:55:43 +0800
Tag:    v3.5.2

MDL-62769 quiz statistics: graph should show all, not last, variant

commit 9eff7d953579d0b84b07eef082053b8d95228917
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Sat, 11 Oct 2014 00:58:30 +0800
Tag:    v3.5.2

MDL-45851 restore: random questions must always be created