Change orange button to use CSS instead of an image
Add helper for determining device pixel ratio
Add HiDPI mixin for handling higher dpi images
Add HiDPI code background
Add HiDPI Ember logo

Also removed drop-shadow filter as it was buggy with the HiDPI
version of the logo and made the logo it self have the drop shadow.
Add HiDPI chapter mark
Add HiDPI footer links
Add HiDPI ajax loader
Add Font Awesome via Fontello

Included config.json for adding more icons
Use Font Awesome for footer links instead of images
Use Font Awesome for 'fork us' instead of image
Use Font Awesome for 'Edit page' instead of image
Add HiDPI ribbons
Add HiDPI navigation background
Use SVG version of background shades if browser supports
Add scale effect on hover to maintain some sort of hover style

Original hover style was a bigger shadow.
Use Compass mixins instead of prefixed CSS
Fix indentation in examples css
Add HiDPI header text
Add HiDPI example arrows