Some slight refactoring for swiftiness
Giving cell a default background color so we know what size it is while the image is loading
Simplifying constant strings
Merge branch 'master' into yay-swift

Conflicts:
	Wallpaper-Demo/Wallpaper-Demo/WPSecondViewController.swift
	Wallpaper/Wallpaper.swift
Adding more tests?
Renaming struct method for readability
Merge pull request #1 from enmiller/yay-swift

Some slight refactoring for swiftiness