undefined _guid error when using module.on in subclasses 

Added a monkey patch to fix error when using events in subclasses.

```
var Parent = Stapes.subclass({});
var Module = Parent.subclass({ "sleep" : function() { this.emit('sleeping', 'very deep'); } });
var module = new Module();
module.on('sleeping', function(how) { console.log("i'm sleeping " + how); });

TypeError: 'undefined' is not an object (evaluating 'this._.guid')
```
 when instantiating subclasses, the constructor relies on variable named includeEvents that is evaluated to false (due to clojure out of scope, I guess)  and therefore does not properly add a _guid, making the use of events to thrown an error. 

Cheers,