Adds slot machines to the game.

What it says on the tin.
It works with coins and shit.

emagging it is top lyl and shoots the coins at you.

Probabilities and values are currently completely arbitrary, feel free to suggest changes.

This does not place them on the map.
This is going to bug out if we decide to change the value of silver to something other than 40. It should use the value from the coin itself rather than use a magic number like this.