Translations for the security messages
minor #1149 Translations for the security messages (b-durand)

This PR was squashed before being merged into the 2.0.x-dev branch (closes #1149).

Discussion
----------

Translations for the security messages

Error messages when an user wants to be authenticated should use the
translations provided by the security component.

Related to #1141.

---

One more thing: I think that we should delete the entry "Bad credentials." in the translation of FOSUserBundle, but all languages in FOSUserBundle don't exist in translations of the security component, and the translation is not the same (diff between de or fr).

Commits
-------

a883bcb Translations for the security messages