Added public static Boolean isTutorial to Dungeon, this Boolean is set
in the 4 buttons found in GameModeScene.
Modified depthFile and gameFile methods in Dungeon. Added tutorial
alternative filepaths.
Added tutorial alternative filepaths to Badges & Rankings.
Modified GamesInProgress to separate gamestate and tutorialstate.
Modified PixelDungeon so lastClass is set separately for normal and
tutorial.
Added key for tutorial lastClass to Preferences.