focusin focusout support for firefox.js

(function(w, d, undefined){
	if( w.onfocusin === undefined){
		d.addEventListener('focus', addPolyfill, true);
		d.addEventListener('blur', addPolyfill, true);
		d.addEventListener('focusin', removePolyfill, true);
		d.addEventListener('focusout', removePolyfill, true);
	}
	
	function addPolyfill(e){
		var type = e.type === 'focus' ? 'focusin' : 'focusout';
		var event = new CustomEvent(type, { bubbles:true, cancelable:false });
		event.c1Generated = true;
		e.target.dispatchEvent( event );
	}
	
	function removePolyfill(e){
		if(e.c1Generated){
			d.removeEventListener('focusin', removePolyfill, true);
			d.removeEventListener('focusout', removePolyfill, true);
		} else {
			d.removeEventListener('focus', addPolyfill, true);
			d.removeEventListener('blur', addPolyfill, true);
			d.removeEventListener('focusin', removePolyfill, true);
			d.removeEventListener('focusout', removePolyfill, true);
		}
	}
})(window, document);