Author: Stephen Bourget
MDL-32135 mod_choice: Open time should be before close time
http://git.moodle.org/gw?p=moodle.git;a=commit;h=dd171628ea30b181fe3400a65039422e84d46dc2
http://github.com/moodle/moodle/commit/dd171628ea30b181fe3400a65039422e84d46dc2
+ 3.1 en [closebeforeopen,mod_choice]