request #6964: Prevent users to enter misspelled emails during registration

During user registration, users might misspell their email address,
leading to a lost email (and maybe a lost user). This changes let the
plateform to suggest a right domain when the user misspell it. This is
will improve user experience.

Based on the javascript lib mailcheck (MIT License)

Usefull links:
- http://blog.kicksend.com/how-we-decreased-sign-up-confirmation-email-bounces-by-50/
- https://github.com/mailcheck/mailcheck

To test it, register as a new user, enter a wrong email address like:
toto@gnail.com, when you leave the input, it will suggest:
toto@gmail.com.

Change-Id: I0edf0821caafca15d151ca21f7cfba5797dd0f59
Merge commit 'refs/changes/16/2516/2' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  request #6964: Prevent users to enter misspelled emails during registration

Change-Id: I309e5d8a8c374ee05a6a2e34edf84cad5e24bebb
This is Tuleap 7.7.99.25

Change-Id: I870c49739cd5e4710ae86b9ec673084902f767be