Update rails to 4.0:

* Add protected_attributes gem dependency;
* Remove deprecated usages of AR .find method;

config/locales/en.yml

@@ -1,5 +1,23 @@
-# Sample localization file for English. Add more files in this directory for other locales.
-# See https://github.com/svenfuchs/rails-i18n/tree/master/rails%2Flocale for starting points.
+# Files in the config/locales directory are used for internationalization
+# and are automatically loaded by Rails. If you want to use locales other
+# than English, add the necessary files in this directory.
+#
+# To use the locales, use `I18n.t`:
+#
+#     I18n.t 'hello'
+#
+# In views, this is aliased to just `t`:
+#
+#     <%= t('hello') %>
+#
+# To use a different locale, set it with `I18n.locale`:
+#
+#     I18n.locale = :es
+#
+# This would use the information in config/locales/es.yml.
+#
+# To learn more, please read the Rails Internationalization guide
+# available at http://guides.rubyonrails.org/i18n.html.
 
 en:
   hello: "Hello world"