Author: Stephen Bourget
MDL-54910 mod_data: Open dates should be before close dates
http://git.moodle.org/gw?p=moodle.git;a=commit;h=2d0bbd3b6e7662229b92eba9a41af905eed2ab01
http://github.com/moodle/moodle/commit/2d0bbd3b6e7662229b92eba9a41af905eed2ab01
+ 3.1 en [availabletodatevalidation,mod_data]
+ 3.1 en [viewtodatevalidation,mod_data]