Improve settings

Soon the Atom settings will use the `ui-variables` to match a theme's look and feel: https://github.com/atom/settings-view/pull/277 This PR fixes a few things and will look like this:

![screen shot 2014-12-18 at 4 12 32 pm](https://cloud.githubusercontent.com/assets/378023/5484719/5957cc76-86d1-11e4-9899-7f183414f513.png)