Author: Stephen Bourget
MDL-49183 Lesson: Add additional events
http://git.moodle.org/gw?p=moodle.git;a=commit;h=1cf8ca343fbf760668e695dbfb93291289e2808b
http://github.com/moodle/moodle/commit/1cf8ca343fbf760668e695dbfb93291289e2808b
+ 2.9 en [eventpagecreated,mod_lesson]
+ 2.9 en [eventpageupdated,mod_lesson]
+ 2.9 en [eventpagedeleted,mod_lesson]