Author: Tim Hunt
MDL-81423 assign: improve valdation message for submissionstatement
http://git.moodle.org/gw?p=moodle.git;a=commit;h=bcc5ded857157319837c4a8ca629f0ea5f54880a
http://github.com/moodle/moodle/commit/bcc5ded857157319837c4a8ca629f0ea5f54880a
+ 4.3 en [submissionstatementrequired,mod_assign]