fix french gramar and orthograph.
fix i18n tag error in editor and settings template
Merge branch 'translation_fr' of https://github.com/MartinDelille/codecombat into translation_fr

* 'translation_fr' of https://github.com/MartinDelille/codecombat:
  "des emails" => "un email"
  player_created
  add email_notifications_description in fr.coffee
  use i18n contribute class in settigs.jade
  various grammar
  fix i18n edito.main_description in editor.jade