Author: Stephen Bourget
MDL-48883 Lesson: Add event for content page viewed
http://git.moodle.org/gw?p=moodle.git;a=commit;h=28c36dd085a6343cc00281f4cdb7b7b4e69f409e
http://github.com/moodle/moodle/commit/28c36dd085a6343cc00281f4cdb7b7b4e69f409e
+ 2.9 en [eventcontentpageviewed,mod_lesson]