Migrate from ledermann/rails-settings to rails-settings-cached which allows global settings

with YAML-defined defaults. Add admin page for editing global settings. Add "site_description"
setting that would show as a paragraph on the frontpage

app/helpers/settings_helper.rb

@@ -14,4 +14,8 @@ module SettingsHelper
   def human_locale(locale)
     HUMAN_LOCALES[locale]
   end
+
+  def hash_to_object(hash)
+    HashObject.new(hash)
+  end
 end