File _service of Package nsis

<services>
  <service name="download_url">
    <param name="url">http://downloads.sourceforge.net/project/nsis/NSIS%203/3.08/nsis-3.08-src.tar.bz2</param>
    <param name="filename">nsis-3.08-src.tar.bz2</param>
  </service>
</services>