Add rules for js prefixes and dispatcher when using jQuery

Imagine this scenario:
- ProfilesController
- `show.html.haml`
- `_request_button.html.haml` included in the `show` template

What I think is dangerous is this:

```coffeescript
show: ->
  new RequestButton()
```

What I would do is include the javascript in the request button partial using

```haml
:coffeescript
  $ ->
    new RequestButton()
```

Now, this is a very simple scenario. It might be that a profile needs a quite complex js structure. In that case I would do:

```coffeescript
show: ->
  new Profile()
```

And put the initialization of the RequestButton in the Profile class.