Git commits in Moodle 3.6.4 by zpottie

commit 24bcd5b772abd2e9d848a5145c6663e37c10f40c
Author: zpottie <zander.potgieter@learningworks.co.nz>
Date:   Thu, 24 Jan 2019 06:55:00 +0800
Tag:    v3.6.4

MDL-58315 core: Add support for custom block classes in Boost