add back emitter

src/emitter.js

@@ -0,0 +1,35 @@
+"use strict";
+
+var eventEmitter = new (require('events')).EventEmitter();
+
+
+eventEmitter.all = function (events, callback) {
+	var eventList = events.slice(0);
+
+	events.forEach(function onEvent(event) {
+		eventEmitter.on(event, function () {
+			var index = eventList.indexOf(event);
+			if (index === -1) {
+				return;
+			}
+			eventList.splice(index, 1);
+			if (eventList.length === 0) {
+				callback();
+			}
+		});
+	});
+};
+
+eventEmitter.any = function (events, callback) {
+	events.forEach(function onEvent(event) {
+		eventEmitter.on(event, function () {
+			if (events !== null) {
+				callback();
+			}
+
+			events = null;
+		});
+	});
+};
+
+module.exports = eventEmitter;