Author: Shamim Rezaie
MDL-68076 core: Introduced \core\notification::cta()
http://git.moodle.org/gw?p=moodle.git;a=commit;h=3fecf7b547d638959e5e3ebc6e52bbd15030289d
http://github.com/moodle/moodle/commit/3fecf7b547d638959e5e3ebc6e52bbd15030289d
+ 3.9 en [calltofeedback,core]
+ 3.9 en [calltofeedback_give,core]
+ 3.9 en [calltofeedback_remind,core]