Add language settings for users, and translate titles to French

test/fixtures/users.yml

@@ -8,6 +8,7 @@
 #  id              :integer          not null, primary key
 #  admin           :boolean          default(FALSE), not null
 #  email_address   :string           not null
+#  lang            :string           default("en")
 #  password_digest :string           not null
 #  username        :string
 #  created_at      :datetime         not null

test/models/user_test.rb

@@ -5,6 +5,7 @@
 #  id              :integer          not null, primary key
 #  admin           :boolean          default(FALSE), not null
 #  email_address   :string           not null
+#  lang            :string           default("en")
 #  password_digest :string           not null
 #  username        :string
 #  created_at      :datetime         not null