Git commits in Moodle 3.1.0 by Kevin Bruton

commit cfd8c0fe094cf8c14bdd59cc1b40c436f8ee5621
Author: Kevin Bruton <kevin.jose.bs@gmail.com>
Date:   Sun, 10 Jan 2016 07:12:58 +0800
Tag:    v3.1.0-beta

MDL-52568 core_cohort: added ability to return all cohorts in WS