Sort out storage and use of user preferred languages.

db/migrate/035_change_user_locale.rb

@@ -0,0 +1,15 @@
+require 'lib/migrate'
+
+class ChangeUserLocale < ActiveRecord::Migration
+  def self.up
+    remove_foreign_key :users, [:locale], :languages, [:code]
+
+    rename_column :users, :locale, :languages
+  end
+
+  def self.down
+    rename_column :users, :languages, :locale
+
+    add_foreign_key :users, [:locale], :languages, [:code]
+  end
+end