Support scoped selectors

[lazd]

With markup such as:

<nav id="menu" class="menu">
  <a href="#" class="menu-title">Furniture</a>
  <nav class="menu">
    <a href="#" class="menu-title">Chairs</a>
  </nav>
  <nav class="menu">
    <a href="#" class="menu-title">Couches</a>
  </nav>
</nav>

The following test should pass:

var spy = sinon.spy();

var menu = document.querySelector('#menu');
Gator(menu).on('click', '> .menu-title', function() {
   expect(event.target.parentNode).to.equal(menu);
});


var titles = menu.querySelectorAll('.menu-title');

for (var i = 0; i < titles.length; i++) {
  dispatch('customEvent', titles[i]);
}

expect(spy.callCount).to.equal(1, 'spy call count after dispatching events on every .menu-title');

This is supported in jQuery and a pull request to add this functionality has been sent against ftdomdelegate Financial-Times/ftdomdelegate#50