Author: Paul Holden
MDL-82225 cohort: convert single cohort deletion to JS & AJAX.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=28ffd21d44e3de7874469fb585d627c759f0b634
http://github.com/moodle/moodle/commit/28ffd21d44e3de7874469fb585d627c759f0b634
+ 4.5 en [delcohortssuccess,core_cohort]
+ 4.5 en [delsuccess,core_cohort]