Author: Petr Škoda
MDL-37717 warn teachers before disabling or deleting their enrolment method
http://git.moodle.org/gw?p=moodle.git;a=commit;h=12c92bca22827a127d3ae06732e298e67219d43e
http://github.com/moodle/moodle/commit/12c92bca22827a127d3ae06732e298e67219d43e
+ 2.6 en [deleteinstanceconfirmself,core_enrol]
+ 2.6 en [disableinstanceconfirmself,core_enrol]
+ 2.6 en [instanceeditselfwarning,core_enrol]
+ 2.6 en [instanceeditselfwarningtext,core_enrol]