Author: Brendan Heywood
MDL-34925 user: Convert bulk user download to dataformat
http://git.moodle.org/gw?p=moodle.git;a=commit;h=12142298ec0092a716a0fecf738f73a55c845d59
http://github.com/moodle/moodle/commit/12142298ec0092a716a0fecf738f73a55c845d59
+ 3.1 en [userbulkdownload,core_admin]