Git commits in Moodle 3.4.3 by Tim Hunt

commit 023c3d4f0dfbb8c4fce9d4ba81e59d86e854c630
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 01 May 2018 02:45:47 +0800
Tag:    v3.4.3

MDL-62275 qtype_calc*: improve validation of formulae


commit fadee607e90a03cbc01534ce84c7991634caf87b
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 10 Apr 2018 21:00:39 +0800
Tag:    v3.4.3

MDL-61928 formslib: shortforms should work with non-editable forms


commit 199b34b5d06812c3a3bcb7d30eb303d14d465685
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 06 Feb 2018 01:30:21 +0800
Tag:    v3.4.3

MDL-61348 quiz reports: fix incorrect groups averages