Fix Orbit's styles side-effects

Hello,

Orbit's styles affect on styling of the slide's content which is wrong IMO.

My case:
```html
<ul class="slides" data-orbit>
    <li>
        <img src="../img/some.png">
        <div>
            <!-- ... -->
            <ul class="some-class">
                <li>blabla</li>
                <li>blabla blabla blabla</li>
                <li>blabla blabla</li>
            </ul>
            <!-- ... -->
        </div>
    </li>
    <!-- ... -->
</ul>
```