Special Modes update

In the create world menu there would be a new tab where you can select certain modes like a deserted island where you have a special preset world where the player could choose between multiple victory conditions.  The player could continue after getting to their chosen victory condition.  The player could also select multiple victory conditions.  Some modes will make it so that it might always be night or certain mobs don't spawn.  If you reach a certain victory condition in a certain mode you will get an advancement/achievement that you will then have in every world.