Git commits in Moodle 3.1.6 by Tim Hunt

commit 4d6d096336f3cf95ae3c021a024a7594831968c3
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Mon, 10 Apr 2017 23:29:16 +0800
Tag:    v3.1.6

MDL-58555 ajax: make ajax web service log entries more useful

commit 7a27817f9874bbbc4091d8dbd4d34313e4eedd32
Author: Tim Hunt <T.J.Hunt@open.ac.uk>
Date:   Tue, 04 Apr 2017 23:20:26 +0800
Tag:    v3.1.6

MDL-58486 user_prefs: always update $USER cache when applicable