Author: Sam Hemelryk
MDL-27161 Improved the 2 new strings in assignment
http://git.moodle.org/gw?p=moodle.git;a=commit;h=f138b7c13b5c35230e086ad14197f732083aae48
http://github.com/moodle/moodle/commit/f138b7c13b5c35230e086ad14197f732083aae48
+ 2.1 en [norequiregrading,mod_assignment]
+ 2.1 en [nosubmisson,mod_assignment]