Git commits in Moodle 3.7.x by Trisha Milan

commit 8faaa5da6591b152414e5ee76e96534b534880d3
Author: Trisha Milan <trishamilan@catalyst-au.net>
Date:   Thu, 11 Apr 2019 14:46:07 +0800
Tag:    v3.7.3

MDL-65310 block_timeline: Hide activities without due date

commit fdb9c3217d1e2593ae37d354da6f54132fbb0809
Author: Trisha Milan <trishamilan@catalyst-au.net>
Date:   Tue, 02 Apr 2019 20:17:18 +0800
Tag:    v3.7.0-beta

MDL-64449 core: Added Session lock debugging option

commit 600de03e0588d1e56e2b2aad7a76067bac1b64a9
Author: Trisha Milan <trishamilan@catalyst-au.net>
Date:   Tue, 19 Feb 2019 11:30:53 +0800
Tag:    v3.7.0-beta

MDL-64894 Theme: Fix unable to expand collapsible topics