Porting core_admin theme to Rails

This was pretty straight forward, mostly just copying files into the right place, but there are a few small things that Middleman does differently than rails.

**Changelog**

* Changed `partial` calls to `render`

From:
```
partial "partials/action_nav_normal_one_row"
```
To:
```
render "partials/action_nav_normal_one_row"
```

* Moved all helper functions from `config.rb` in Middleman to the `application_helper.rb` in Rails

* Added a `pages_controller.rb` and updated the routes file to serve the static pages

@WesleyG, feel free to hit me up with any questions you have on this. I'm going to merge this in to master right away, so you'll be able to pull down the repo and boot up the app.