Work in progress.

Finished:
 -Article html no longer goes over javascript bridge.
 -Articles, images, css and js files loading/displaying properly.
 -Single query article download - the reason is it is tricker
  to be splitting lead/non-lead section retrieval across 2
  requests and also if the point of this refactor is to
  streamline away low-performance javascript, it seems
  antithetical to be amending/injecting late arriving
  non-lead section html via javascript. Additionally,
  now that we're using gzip encoding properly the download
  is much smaller than it was when we first split the
  request in 2.
 -Javascript css transforms - via DOMContentLoaded event,
  which fires before window.onload! :)

Not yet finished:
 -Editing workflow preview screen using webview loadData.

Change-Id: Ie5aa09d7ac36f06930ac1bfbe09c0259240253fe