Market pricing in place, not perfect

- MarketSetup sets up the prices and quantities for a given planet, and
has arrays for which items can be bought and sold on that planet (based
on the game rules).
- StarMapController prints out the goods and their prices when you click
the BUY THINGS button on a planet view.
- Still TO DO:
--- Narcotics always seem to be free for some reason
--- Quantities are just 10 for now, need to discuss how we want to
generate them
--- Need to discuss how government type affects prices/quantites