added whole system from ola4doc

sys/node_modules/array-differ/index.js

@@ -0,0 +1,7 @@
+'use strict';
+module.exports = function (arr) {
+	var rest = [].concat.apply([], [].slice.call(arguments, 1));
+	return arr.filter(function (el) {
+		return rest.indexOf(el) === -1;
+	});
+};