Experimental: 'on' as alias to 'addListener'

lib/events.js

@@ -75,6 +75,7 @@ process.EventEmitter.prototype.addListener = function (type, listener) {
   return this;
 };
 
+process.EventEmitter.prototype.on = process.EventEmitter.prototype.addListener;
 
 process.EventEmitter.prototype.removeListener = function (type, listener) {
   if ('function' !== typeof listener) {

test/simple/test-event-emitter-add-listeners.js

@@ -11,7 +11,7 @@ e.addListener("newListener", function (event, listener) {
   events_new_listener_emited.push(event);
 });
 
-e.addListener("hello", function (a, b) {
+e.on("hello", function (a, b) {
   console.log("hello");
   times_hello_emited += 1
   assert.equal("a", a);