Segmented buttons

Note the entire intuition is for it to be used as a form input. Syntax:
```html
<div class="button-group-segmented">
     <label><input type="radio"/><button>Active</button></label>
     <label><input type="radio"/><button>Inactive</button></label>
</div>
```
I know using a `label` tag isn't amazingly nice but it is the only thing which works because when you click on a `label` any `input` descendant of type `checkbox` or `radio` is automatically selected. On the bright side it requires no JavaScript, which I personally think outweighs the negatives tenfold.