Continue backbutton hookup, this commit includes debugging provisions
that deliberately cause malfunctions, including tests, and must be
removed before pull.

The problem this demonstrates is that programmatic triggering of the
"backbutton" event is *not* causing app.js onBackKeyDown() to fire, as
it should, on my Nexus 7. However, the same contrivance is achieving the
intended effect on the desktop (security-inhibited) browser.