MDL-40054 events: changed instances_list to instance_list
MDL-40054 mod_lesson: added ability to generate a lesson module in PHPUnit
MDL-40054 mod_lesson: replaced 'view all' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'update grade' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'grade view' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'update highscores' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'view highscores' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'view' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'start' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'end' add_to_log call with an event
MDL-40054 mod_lesson: replaced 'update email essay grade' add_to_log call with an event