Created a sub-level sidebar for the Settings page.

It looks like this:

![screen shot 2014-12-30 at 11 55 26](https://cloud.githubusercontent.com/assets/246103/5578204/ca3dc98e-901a-11e4-9474-a2d9e55a9f6e.png)

For now, the settings page is still altogether, they're just jump links.

- Not responsive.
- A bit messy adding sidebars to pages, I wonder if we could create a mechanism for this?
That's how Elixir compiles the CSS.