If we want to support namespaced import:
```scss
.twbs {
@import 'bootstrap';
}
```
We cannot use `selector &`, see sass/sass#1817.
`fieldset[disabled] &` is not needed as we no longer support IE8.
To the middle of nowhere
To the middle of my frustrated fears
And I swear you're just like a pill
Instead of makin' me better,
You keep makin' me ill
You keep makin' me ill
adds .label-pill to replace .badge
