Issue with route binding causing failure

[jonbnewman]

Scenario: route binding against an element with a state option whose value is null.

Example:

<router module="MyRouter">
<a data-bind="route: someProperty"></a>
</router>

fw.router.register('MyRouter', function MyRouter () {
  var self = fw.router.boot({ /* ... */});
  self.someProperty = fw.observable(undefined);
});

This causes a binding error and breaks the application.