Changed all of the getEntity() methods in

CraftAnimals.java,
EntityChicken.java,
EntityCow.java,
EntityMushroomCow.java,
EntityPig.java,
EntityWolf.java,
EntityOcelot.java,
EntitySheep.java,
EntityHorse.java,

that used to be of form:

public static CraftEntity getEntity(Entity entity, CraftServer server) {
        return new CraftEntityName(server, (CraftEntityName) entity);
    }
    
To no longer be static, and changed them to form:

public CraftEntity getEntity(CraftServer server) {
        return new CraftEntityName(server, (CraftEntityName) this);
    }
    
This way, the getEntity() method in Entity.java, which was repeated
logic of isAnimal() in Entity.java, could be removed.