Merge pull request #76 from jocelynlih/paul

Upgrading to Xcode6 Beta6
starting on the two scenes again
added game over scene
Merge pull request #78 from jocelynlih/hallas/scenes

Game Over Scene
level finished scene
updated level select scene
Adding playground for particle effects chapter
Merge pull request #79 from jocelynlih/ankur-add-playgrounds

Adding playgrounds
Merge branch 'master' of https://github.com/jocelynlih/SwiftGameBook into paul
Fixed the un-jumpable death trap, replaced all levels with our one level created by Jocelyn so we have four copies of the same level.