Add predator and factories

src/aliensimulator/AlienSimulator.java

src/aliensimulator/aliens/AlienFactory.java

src/aliensimulator/predators/HishQuTen.java

src/aliensimulator/predators/Predator.java

src/aliensimulator/predators/PredatorFactory.java

src/aliensimulator/predators/Yautja.java