Teams, naive scoring, a game that goes to the end

+ Create a team class in players.py that allows for easy scoring
calculations and team names (whimsy!)
+ add a naive scoring method that pretends nil bids don't exist (TODO:
implement nil bidding support with a user defined exception)
+ game now goes until someone hits the end score
+ dealer advances automatically without having to enter dealer over and
over again
+ rename some of the attributes so they are easier to understand
+ update spades.py to use all the new hotness