File _servicedata of Package zcash

<servicedata>
  <service name="tar_scm">
    <param name="url">https://github.com/zcash/zcash.git</param>
    <param name="changesrevision">16b49eadd56086aae10f2907e5b8e77b773f1813</param>
  </service>
</servicedata>