Author: Mark Nelson
MDL-41101 mod_assign: replaced 'view grading form' add_to_log call with an event
http://git.moodle.org/gw?p=moodle.git;a=commit;h=1045b6e333254f461446edbf6f9d28abdaa4fc7d
http://github.com/moodle/moodle/commit/1045b6e333254f461446edbf6f9d28abdaa4fc7d
+ 2.7 en [eventgradingformviewed,mod_assign]