code: function matches(el, target, selector)
  {
  	var elements = el.querySelectorAll(selector);
  	return arrayIndexOf(elements, target) !== -1;
  }
docs: Matches target element against CSS selector starting from element el
  
  @param  {DOMElement} el     Root DOM element
  @param  {DOMElement} target Target DOM element
  @param  {string} selector   CSS selector
  @return {boolean}           True if target element matches CSS selector, false otherwise