Git commits in Moodle 3.9.7 by Neill Magill

commit b861c1dec7d0169ad0b1c3945ca37f5e23327b49
Author: Neill Magill <neill.magill@nottingham.ac.uk>
Date:   Thu, 04 Apr 2019 18:33:31 +0800
Tag:    v3.9.7

MDL-64336 assign: Add missing PHP doc


commit 808a335c906eaa8443afebd7cdf467c2cebe4e2d
Author: Neill Magill <neill.magill@nottingham.ac.uk>
Date:   Thu, 04 Apr 2019 18:31:49 +0800
Tag:    v3.9.7

MDL-64336 assign: Teachers should be able to see all submissions


commit 3b55f2847a4c1b539da24da4f57b95fea1ac6b60
Author: Neill Magill <neill.magill@nottingham.ac.uk>
Date:   Mon, 10 Dec 2018 17:27:36 +0800
Tag:    v3.9.7

MDL-64336 assign: Submissions should be visible while frozen