Added game support: Yoxii

[Olaf-007]

This will add a subfolder "yoxii" with all files that are needed to

1. Calculate the NN for Yoxii
2. Play the game.

• YoxiiGame.py (Subclass of Game in parent folder - dependent!)
• YoxiiLogic.py (All the nessessary tools to manipulate the game state)
• YoxiiPlayers.py (Human Player and Random Player)
• mainForYoxii (an adapted main.py as in the parent folder for Yoxii)
• pitForYoxii (script to test the NN using the Arena class of the parent folder)
• pytorch/YoxiiNet (the NN architechture for training Yoxii games, almost the same as for Othello)