Author: Cameron Ball
MDL-41945 mod_assign: Check if submission has been modified
This patch adds a check that stops a user submitting an assignment
if someone else has modified it in the meantime.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=16b36d376a9ccc00bc5016a90aff8995edad1094
http://github.com/moodle/moodle/commit/16b36d376a9ccc00bc5016a90aff8995edad1094
+ 3.2 en [submissionmodified,mod_assign]
+ 3.2 en [submissionmodifiedgroup,mod_assign]