Avoid having test-in-browser shutdown the autoupdate subscription,
so that developers still get hot code pushes when writing tests.

Fix livedata tests.

Add a sanity check to deciding when to reload: only reload if there is
an available client version marked "current".  (Otherwise if the
server fails to publish any valid client versions, perhaps as a bug in
a forked autopublish package, the client will go into an infinite loop
of reloads).

Update QA notes.