Author: Sam Hemelryk
MDL-26770 enrol - Added support for bulk operations by enrol plugins
http://git.moodle.org/gw?p=moodle.git;a=commit;h=75ee207b815084874e9053c466cc75a2ac60936c
http://github.com/moodle/moodle/commit/75ee207b815084874e9053c466cc75a2ac60936c