More customization options: conferences, divisions, and playoff length

Until today, Basketball GM was hardcoded to always have 2 conferences, 6 divisions, and 16 teams in the playoffs. If you wanted to set up a league with a different structure, you were out of luck.

But today that has changed! You can have any number of conferences and divisions, and the number of teams in the playoffs can be any power of 2 (2, 4, 8, 16, 32, etc). Unfortunately this is only customizable by making a league JSON file, but it's not that hard, I promise. Here is the documentation and here is an example file with 3 conferences, 6 divisions, 12 teams, and a 4 team playoff.

Please let me know if you notice bugs related to this!