def configurable(klass, key, opts={})
      opts[:key] = key
      opts[:label] ||= key
      Config.configurables ||= {}
      Config.configurables[klass.full_name] ||= []
      Config.configurables[klass.full_name] << opts
    end
def configurable(klass, key, opts={})
      opts[:key] = key
      opts[:label] ||= key
      Config.configurables ||= {}
      Config.configurables[klass.full_name] ||= []
      Config.configurables[klass.full_name] << opts
    end
Options for hash:
   :label => 'Some Configurable'
   :default => 'default value'