Author: Jun Pataleta
MDL-86512 mod_assign: Make the select column header name more accessible
http://git.moodle.org/gw?p=moodle.git;a=commit;h=8c5c5eaee4e252dab9d053d7a2cd529ee8ccc3db
http://github.com/moodle/moodle/commit/8c5c5eaee4e252dab9d053d7a2cd529ee8ccc3db
+ 4.5 en [bulkactionsselection,mod_assign]