Author: Davo Smith
MDL-35288 drag and drop upload - adjust error message text when attempting to upload a folder
http://git.moodle.org/gw?p=moodle.git;a=commit;h=91813c1b4bf195e91933c780a716f6c2104d5c0e
http://github.com/moodle/moodle/commit/91813c1b4bf195e91933c780a716f6c2104d5c0e
+ 2.4 en [upload_error_invalid_file,repository_upload]