Update README.md
Update README.md
Add Double arguments for CGStructs on 32bit
Update README.md
Update README.md
Update README.md
Change SpriteKite to SpriteKit in readme.
Merge pull request #1 from JoshTheGeek/patch-1

Change SpriteKite to SpriteKit in readme
Merge pull request #2 from seivan/master

Merge readme changes to develop.