Expanded easing keywords for transitions.

* ease-in-out-back
* ease-in-out-circ
* ease-in-out-expo
* ease-in-out-sine
* ease-in-out-quint
* ease-in-out-quart
* ease-in-out-cubic
* ease-in-out-quad
* ease-out-back
* ease-out-circ
* ease-out-expo
* ease-out-sine
* ease-out-quint
* ease-out-quart
* ease-out-cubic
* ease-out-quad
* ease-in-back
* ease-in-circ
* ease-in-expo
* ease-in-sine
* ease-in-quint
* ease-in-quart
* ease-in-cubic
* ease-in-quad

See [easing demos](http://easings.net) for live examples.

```crush
transition: .2s ease-in-quad;
```

```css
transition: .2s cubic-bezier(.550,.085,.680,.530);
```