adding some game object management stuff
adding Xcode project files
added GameObjectCollection for managing sets of bricks/paddles/balls

this might be going overboard with the generic utility classes and such…
adding collision logic, stubbed out the renderer
adding Xcode stuff to gitignore
cleaning up the collision stuff a bit
ignore xcode breakpoint list files
some player management things
fixed a linking error
adding some basic layout stuff
Merge pull request #11 from t3kt/master

implemented a bunch of game object management, collision logic, and added a stub for a renderer