stderr should be EventEmitter even if it doesn't emit anything

src/node.js

@@ -153,12 +153,11 @@
       return stdout;
     });
 
-    var stderr = process.stderr = {
+    var events = NativeModule.require('events');
-      writable: true,
+    var stderr = process.stderr = new events.EventEmitter();
-      readable: false,
+    stderr.writable = true;
-      write: process.binding('stdio').writeError
+    stderr.readable = false;
-    };
+    stderr.write = process.binding('stdio').writeError;
-
     stderr.end = stderr.destroy = stderr.destroySoon = function() { };
 
     process.__defineGetter__('stdin', function() {