Git commits in Moodle 3.5.1 by Zig Tan

commit 749c7cc5a942d3429e8a50131832ed68886cd585
Author: Zig Tan <zig@moodle.com>
Date:   Wed, 27 Jun 2018 15:50:31 +0800
Tag:    v3.5.1

MDL-44081 assign: Fix Grader annotation button accessibility ordering

commit fd77e38fc9b27edb5ae0a790cb5a9d085eb2ac2d
Author: Zig Tan <zig@moodle.com>
Date:   Fri, 15 Jun 2018 10:10:59 +0800
Tag:    v3.5.1

MDL-61482 mod_assign: Clean html in offline grading CSV

commit e275b0c4a63b35dac1145e35501ce45f9cf24058
Author: Zig Tan <zig@moodle.com>
Date:   Fri, 15 Jun 2018 09:46:29 +0800
Tag:    v3.5.1

MDL-58702 backup: Fix restoration of role mappings labels