Author: Mark Nelson
MDL-40054 mod_lesson: replaced 'start' add_to_log call with an event
http://git.moodle.org/gw?p=moodle.git;a=commit;h=9c192d812bdc52178b09a6f30f0b2da10ccb9b09
http://github.com/moodle/moodle/commit/9c192d812bdc52178b09a6f30f0b2da10ccb9b09
+ 2.7 en [eventlessonstarted,mod_lesson]