Git commits in Moodle 3.1.1 by Tim Hunt

commit da1eeea0ff3d292b7669e478abc114872dd9cc8f
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 10 Jul 2018 01:37:45 +0800
Tag:    v3.1.14

MDL-62880 qtype_ddwtos: drop support for legacy import format

commit b779dc805ed58dc85710aa53e8fff1025a608c2c
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 03 Jul 2018 01:55:22 +0800
Tag:    v3.1.13

MDL-62820 question import: properly escape output

commit b7bbe9fd9466036a84fe7bc4619b376f05b7049f
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 01 May 2018 02:45:47 +0800
Tag:    v3.1.12

MDL-62275 qtype_calc*: improve validation of formulae

commit 330216eb8a2fc770c9ac4d1639d4df73d7e29aba
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Sat, 28 May 2016 02:55:25 +0800
Tag:    v3.1.1

MDL-54756 moodle_url: remove dangerous trim from make_file_url

commit fb91edbe501a8e9199048b895107bc4e941ee08b
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 17 May 2016 06:14:22 +0800
Tag:    v3.1.1

MDL-54605 quiz regrading: incorrect DB query

commit f073424c0851e2b534e9caf15825055aeec6d976
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Sat, 14 May 2016 03:36:30 +0800
Tag:    v3.1.1

MDL-54582 accesslib: improve performance of load_course_context

commit 6760e6db3470534722606321b1a3ce3b550f2e30
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Thu, 12 May 2016 01:07:23 +0800
Tag:    v3.1.1

MDL-53938 qformat_gift: handle multi-choice MR with one 100% choice