Feature/parallax

## Overview

This pull request adds three new html templates, a fly-out side nav and various supporting css and SVG files. 

## New pages

* Academic Discovery Center : Category Page
* Academic Discovery Center : Article
* Parallax Sample Page
* Side-nav Fly Out (visible by visiting the ADC article page and clicking the "Guide To BYU-I" button).

## Full screen template

The `FullWidthLayout.html` template is exactly like `MainLayout.html` except the `<main>` tag has an additional class (`full-width`)–making the main tag full screen. This allows children tags to stretch full width. Wrap any content you need to align horizontally with existing vertical alignment points inside an element with the class `sub-content`. (see image below)

![new-templates-description](https://cloud.githubusercontent.com/assets/4827/5492851/51d263b4-86a2-11e4-9c6a-6a495733796a.png)

## Parallax Images

We are using javascript library [skrollr](https://github.com/Prinzhorn/skrollr) to create the parallax effect. Parallax images are defined as background images and could be specified inline, or via css–whatever makes most sense for the implementers. 

Design has yet to define a standard aspect ratio for parallax background images. When they do, a small amount of work will be needed to fine tune the parallax motion and also tweak the background image behavior at smaller media sizes.