errorClass option can't handle more than 2 class names

Hi , I request to reopen https://github.com/jzaefferer/jquery-validation/pull/280 : 

please see the case at http://jsbin.com/aLoMOwe/3 , more than 2 error classes won't work correctly. 
```
$(".selector").validate({
   errorClass: "invalid red anotherClass"
})
```
jquery v1.10.2
jquery.validation v1.11.1
chrome30.0.1581.2 dev-m

![error](https://f.cloud.github.com/assets/920690/1089790/4698025c-164a-11e3-8885-e000dd119b76.jpg)