Adds a single, solitary ball.
Adds a static status layer to the top of the Game.
Ensure that our hero only runs along the ground.

Fixes #22
Added collision detection to trigger game over.

Fixes #23.
Deleted files accidentally added in commit 6af3e84.
Change the collisions vector to be a pointer for performance reasons.
Update README.md
Merge branch 'master' of https://github.com/Grauniad/hashtag-warrior

Merged (removed) the rotation calculations

Conflicts:
	hashtag-warrior/Game/Layers/GameLayer.mm