JamyGolden

// Retina Sprite
// Mixin takes a two sprite maps, one normal and one retina. It then swaps 
// out the sprite images, repositions and resizes the images accordingly
//
// Rules
//
// Image names within the sprites should match. For example logo.png should 
// exist within both folders. If the image doesn't exist within the retina 
// sprite, the image will fallback to the image that does exist.
//