Created Superclass Trader which Player and Mercenary extend.
Trader has a name and skills which are stored in a Skill List.
Changed the way you get a player's skill level.
Created PlayerShip which extends SpaceShip. PlayerShip has a crew which is an arraylist of crew members. The max number of crew is determined by the ship type's crew() attribute.
Player has an effective skill which is the largest skill of him and his ship's crew members.