Add failing tests for immediately-available pushState and replaceState results.

This is for issue #781.

Backbone routing methods typically need to know the current state of the URL after they've been triggered.  This happens before the next turn of the event loop.

If you write a simple function to run in a Chrome or FF, the behavior is simple.  As soon as you execute pushState or replaceState (and, presumably all of the other history methods), the results of that state change are available on the very next line of code.