Field cleanup

* Ditch ``SubsidyChildren`` in favor of ``GSCsubsidy``.
* Add ``GSCspecial`` field.  Note that it's not in every scrape.
* Get rid of ``GSCtrans`` field in favor of ``Transportation``.
* Supress ``PrimaryQualityContact`` in output, add ``GSCcontact``
  field.
* Equate ``PublishedRating`` to ``STARS``