module Middleman::Configuration::Global

def self.included(app)
  app.send :extend, ClassMethods
end

def config
  self.class.config
end

def method_missing(method, *args)
  if config.defines_setting? method
    config[method]
  else
    super
  end
end

def respond_to?(method, include_private = false)
  super || config.defines_setting?(method)
end

def set(key, value=nil, &block)
  value = block if block_given?
  config[key] = value
end