Author: Andrew Nicols
MDL-51117 JavaScript: Convert alert to M.core.alert in dndupload
This also updates a language string to use string params instead of
hard-prefixing.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=296af14b195f625c71068e6c1305ed58722eceaf
http://github.com/moodle/moodle/commit/296af14b195f625c71068e6c1305ed58722eceaf
+ 3.1 en [namedfiletoolarge,core]