Git commits in Moodle 3.10.x by Jamie Stamp

commit c2ba78902c02cd9e895e7cbacefd6b8d2ed9e804
Author: Jamie Stamp <jamie.stamp@catalyst-eu.net>
Date:   Wed, 07 Oct 2020 23:23:18 +0800
Tag:    v3.10.0-beta

MDL-68665 assignfeedback_editpdf: Fix systemsstamp URLs

commit 12fb5964f23a0e7be7fb5958dae59f73da752609
Author: Jamie Stamp <jamie.stamp@catalyst-eu.net>
Date:   Wed, 07 Oct 2020 23:21:18 +0800
Tag:    v3.10.0-beta

MDL-68665 assignfeedback_editpdf: Add filearea to persist stamps

commit 2c8db06e7ad582d32e0c7abb2806592eb53a6e5a
Author: Jamie Stamp <jamie.stamp@catalyst-eu.net>
Date:   Mon, 28 Sep 2020 21:32:28 +0800
Tag:    v3.10.0-beta

MDL-68665 assignfeedback_editpdf: Improve caching on stamps