- Renamed PublicationTools.process_xml() into PublicationTools.decode_xml()
- PublicationTools.process_url() now calls decode_xml internally and
  doesn't return a list of xml anymore
- Renamed PublicationTools.__call__() into PublicationTools.process_xml() for consistency
- Adjust white spaces for vertical alignement of parameters
- Remove double white line between method definitions
- Renamed some two letter variables to reduce pylint comments