Vanilla Game Changes

Vanilla Game Changes:
 * There is now a Desert Chest in the Dungeon.
 * There is now a Confection Chest in the Dungeon, too.
 * The Hallow/Confection Chest will be hidden until the Wall of Flesh had been defeated.
 * When the Wall has been defeated, the Confection/Hallow Chest will spawn in, depending on which has been spawned in the world.