test: Clean up documentation and simplify
test: Clean up documentation and simplify

* Document why the ajax fetch for scripts has to use <script>
  (or sync XHR).
* Remove this hack for the second script, as that one doesn't
  need it.
* Fix typo.
* No need for piping into a new Deferred with .then(), using
  Promise.done() instead.

yangxing-star/jquery-json,timedepths/jquery-json,jkesselring/jquery-json,an-yun/jquery-json,timedepths/jquery-json,Krinkle/jquery-json,allsmy/jquery-json,yangxing-star/jquery-json,jkesselring/jquery-json,Krinkle/jquery-json,an-yun/jquery-json,allsmy/jquery-json