Add and remove isotope-hidden class

add-remove-isotope-hidden-class

			var itemReveal = Isotope.Item.prototype.reveal;
			Isotope.Item.prototype.reveal = function() {
			  itemReveal.apply( this, arguments );
			  $( this.element ).removeClass('isotope-hidden');
			};

			var itemHide = Isotope.Item.prototype.hide;
			Isotope.Item.prototype.hide = function() {
			  itemHide.apply( this, arguments );
			  $( this.element ).addClass('isotope-hidden');
			};