First AI Iteration

Works against all AI's/maps I could test. Greedily looks 30 moves into
the future per planet-planet interaction on increments of 1/5 to 5/5
the planet's total ships. Not extremely robust, but seems to do the
trick and shows great promise for the World class. Next steps will be
to figure out how to test AI in bulk quantities (all AI/map
combinations) and start moving to actual AI concepts.