IE8 Compatibility

Getting IE8 support with the help of some extra dependencies:

 * [component/bind](https://github.com/component/bind) for `Function#bind`
 * [component/trim](https://github.com/component/trim) for `String#trim`
 * [stephenmathieson/normalize](https://github.com/stephenmathieson/normalize) to help the `keydown` event get `target`, `which` and `preventDefault` correctly