Author: Davo Smith
MDL-31641 filemanager - display help message when drag and drop upload is not supported
http://git.moodle.org/gw?p=moodle.git;a=commit;h=2e8da707a0d796747eb6cef2f16be8f169217cf1
http://github.com/moodle/moodle/commit/2e8da707a0d796747eb6cef2f16be8f169217cf1
+ 2.4 en [dndnotsupported,core]
+ 2.4 en [dndnotsupported_help,core]
+ 2.4 en [dndnotsupported_insentence,core]