Triggering change does not call user's change callback

When I create a knob like this:

``` html
<script>
    $(".dial").knob({
        'change' : function (v) { console.log(v); }
    });
</script>
```

And I trigger a change:

``` html
<script>
    $('.dial')
        .val(27)
        .trigger('change');
</script>
```

I think that my change callback should be called, but it isn't.

Here is and example: http://codepen.io/ThomasKliszowski/pen/GgpjdX
