Add superposition to ball

[HuangJunye]

@boland25 @filemaster I am going to implement ball superposition, but that branch (feature/ballSuperposition) is very different from the most updated branch in feature/newUI. I created a new branch feature/superposedBall and I will re-code the superposition.

However, I found the branch refactor/gameManager is based on feature/ballSuperposition. I can't remember what we did in refactor/gameManager branch. Shall we merge it to develop or feature/newUI?

[boland25]

@HuangJunye that branch refactor/gameManager can be abandoned. we can delete. its something that I started that I never finished and @filemaster made a new branch with his work that is better than mine.

I will delete it. Also I can go through and delete the branches we aren't using anymore, clean it up