this lib will disappear soon in favour of a new one inspired by pjax.
pushState + fetch
pjax was yesterday (and jquery dependent). pfetch is today.
This library started as an expansion of this snippet by Alex Normand.
This library left some basic problems:
hrefup the event bubbling chain, resulting in normal unajax'd behaviour
responseType = 'document'isn't applicable (cough fetch) we use the HTML parser to polyfill it.