Author: Tim Hunt
MDL-64464 drag-drop qtypes: allow <span lang=".."> id draggables
This is for accessibility, so that screen readers can read the drag
items with correct pronunciation.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=6f60c7a6f24086e5f59ad34d0cd575602f3a2996
http://github.com/moodle/moodle/commit/6f60c7a6f24086e5f59ad34d0cd575602f3a2996
+ 3.5 en [formerror_disallowedtags,qtype_ddimageortext]