File _service of Package libass

<services>
  <service name="tar_scm">
    <param name="filename">libass</param>
    <param name="scm">git</param>
    <param name="submodules">disable</param>
    <param name="url">https://github.com/libass/libass.git</param>
    <param name="revision">master</param>
    <param name='versionformat'>0.17.x+git.%ci~%h</param>
    <param name="changesgenerate">enable</param>
  </service>
  <service name="recompress">
    <param name="file">*tar</param>
    <param name="compression">xz</param>
  </service>
  <service name="set_version"/>
</services>