Git merges in Moodle 3.1.13 by Eloy Lafuente (stronk7)

commit 93b943b3228c65415a901581e21f2a7fb5942f7a
Author: Eloy Lafuente (stronk7) <stronk7@moodle.org>
Date:   Sat, 07 Jul 2018 12:48:44 +0800
Tag:    v3.1.13

Merge branch 'install_31_STABLE' of https://git.in.moodle.com/amosbot/moodle-install into MOODLE_31_STABLE

commit 8137f98b1cffa5fb03cfafd41bd8cee6630c52c1
Author: Eloy Lafuente (stronk7) <stronk7@moodle.org>
Date:   Mon, 21 May 2018 19:40:28 +0800
Tag:    v3.1.13

Merge branch 'MDL-62500-31' of git://github.com/andrewnicols/moodle into MOODLE_31_STABLE