Minimise orphaned enhancements, and show warning

Using a post-order depth-first enhancement sweep should minimise cases
where the DOM node is removed before the enhancement is applied.

If it manages to happen anyway (so the enhancement hangs around) then
the 30-second cleanup sweep produces a warning, as there's probably a
problem with one of the renderers.
Update jsonary.js
A couple of bugfixes
AJAX: use error response, define `document.error`
Update jsonary.js
Update renderers to improve state-saving
Include `title()` function for schema lists