WORKING Players + Properties Classes & Arrays

- Working property purchase function, properties array, players array.
  - All players have an ID to be used to identify who owns what.
  - Initialises all players starting balance based on the amount specified by the class prototype.
  - Properties need to be added into array.
  - Code needs to be integrated into the main file, but that is looking quite promising.
- A tiny bit of selling function code is there. Still working on that.
- Purchase costs should probably be turned into an array for easier addressing.
- Mortgage costs may be a bit more difficult since they're not static. I'll look into that.