Expose getConfiguration as a static method on Backbone.Stickit

I really like the simplicity of this, but I have an edge case where I need to use the handlers in an external script.

I want to get the same configuration that would have been returned internally and so it would be really useful to have the getConfiguration as a static method on the namespace.

```javascript
Backbone.Stickit.getConfiguration($el).getVal($el)
//=> value depending on $el
```