Check email

Warning : includes PR #32

- Update User class with AdvancedUserInterface implementation and new fields : isEmailValidated and token.
- Set users account unvalidated by default, and generate a validation token
- Include encrypted informations in mails and set up validation link
- Add validation route with UserController action that checks tokens validity then set user account as validated
- Translates Authentication error messages (Bad credentials & User account is disabled.)