Author: Tim Hunt
MDL-59929 signup: inprove usability when duplicate email entered
http://git.moodle.org/gw?p=moodle.git;a=commit;h=e3993969d676df43f6a1f6713d7c8df9f214f6cd
http://github.com/moodle/moodle/commit/e3993969d676df43f6a1f6713d7c8df9f214f6cd
+ 3.2 en [emailexistssignuphint,core]
+ 3.2 en [emailexistshintlink,core]