Minified lib returns an empty string

Hi there,

I have found that latest version of minified [handlebars.**min.js**](http://builds.handlebarsjs.com.s3.amazonaws.com/handlebars.min-v4.0.4.js) surprisingly returns an empty string every time on each compile operation.

For example:

``` javascript
var tpl = Handlebars.compile('{{foo}}');
var output = tpl({foo: 'bar'});
console.log(output === ''); // true
```
