MBS-5960: url-escape more things Ian forgot in writing the wikipedia extract code

apparently I had an aneurysm that day or something, jeez
Merge remote-tracking branch 'ian-bb/mbs-5960-wikipedia-url-escaping-again' into beta

* ian-bb/mbs-5960-wikipedia-url-escaping-again:
  MBS-5960: url-escape more things Ian forgot in writing the wikipedia extract code