def parsed_www_prefix(params)
      prefix = "#{www_prefix}"
      params.each do |key,value|
        prefix.gsub!(":#{key}", value.to_s)
      end
      prefix
    end
def parsed_www_prefix(params)
      prefix = "#{www_prefix}"
      params.each do |key,value|
        prefix.gsub!(":#{key}", value.to_s)
      end
      prefix
    end
Get the prefix of your pages with interpreted variables given as params.
 You normally don't want to call it yourself. Instead use the
 Humpyard::Page.human_url which will put the current ::I18n.locale into
 the params.