Author: Amaia Anabitarte
MDL-80250 course_format: Create new section_viewed event
http://git.moodle.org/gw?p=moodle.git;a=commit;h=522a7ec0104b9cfaab5607ab2a56a1373c2223cb
http://github.com/moodle/moodle/commit/522a7ec0104b9cfaab5607ab2a56a1373c2223cb
+ 4.4 en [eventsectionviewed,core]