Working header updates.

Moved gdocs to the background to provide shared and persistent auth
services. Otherwise the accessToken wasn’t available to the background
page for sending updates. TODO: consider moving more of the xhr to the
background and caching the citation. That way the window can close more
promptly after saving a note. Also ran into a performance issue with
angular. It wasn’t redrawing the whole butter message thus leaving a
striped background on color change. Hacked the parent element to force
a full redraw.