Author: Andrew Davis
MDL-45282 core_user: fixed up some oddities in the bulk user messaging screen
http://git.moodle.org/gw?p=moodle.git;a=commit;h=f624f569994943b3f5516fd7b9f15387c9c12235
http://github.com/moodle/moodle/commit/f624f569994943b3f5516fd7b9f15387c9c12235
+ 2.7 en [sitemessage,core]