Author: Dmitrii Metelkin
MDL-77130 cohort: add custom fields
http://git.moodle.org/gw?p=moodle.git;a=commit;h=c11d4284be616210d1a9714527d92e5278381e72
http://github.com/moodle/moodle/commit/c11d4284be616210d1a9714527d92e5278381e72
+ 4.2 en [cohort_customfield,core_admin]
+ 4.2 en [cohort:configurecustomfields,core_role]