Pod update.
Using older cocoapods.
Asset catalog tweak.
Replacing ObjC LAGradientView with Swift version.
Cleanup for minor issues that came up while running through the tutorial for the first time.
Updating to AsyncDisplayKit 1.0
Adding comment about using custom layout outside this project.
Organizing files.
Tweaking layout.
Adding more comment markers for tutorial.
Updates for iOS 8.1
Sketch design, app icon.
Adds app icon.
Merge branch 'master' into Start2