Added popup image. Doesn't look good yet
Merge remote-tracking branch 'origin/SpriteKitAlpha' into SpriteKitAlpha
Added red and green buttons to the game over/quit popups
changed the initial time back to normal
Merge remote-tracking branch 'origin/SpriteKitAlpha' into SpriteKitAlpha
Go back to home screen when you quit the game
Merge remote-tracking branch 'origin/SpriteKitAlpha' into SpriteKitAlpha
Combined my popup images with Shannon's commit
Merge remote-tracking branch 'origin/SpriteKitAlpha' into SpriteKitAlpha