NEVERHOOD: More work on saveload, saving works, loading not yet (from the GMM, in-game isn't finished yet)
NEVERHOOD: Improve frame-exact seeking for Scene2802

Thanks to clone2727 for his help!
NEVERHOOD: Add support for the demo version

- Remove debug resource dumping code
- Fix Scene1501 (pictures without sound weren't displayed/too fast)
- Move main loop to mainLoop method
NEVERHOOD: Remove obsolete _keyState
NEVERHOOD: Implement savegame loading via GMM (in-game saving/loading still TODO)
NEVERHOOD: Implement resource cache purging and purge it after each scene
NEVERHOOD: Rename some CollisionMan methods/fields

- Remove fallback detector (I think it's not needed)
- Rename Scene insertMouse methods
NEVERHOOD: Merge CollisionMan into Scene class
NEVERHOOD: Update todo.txt
NEVERHOOD: Remove some obsolete TODOs
NEVERHOOD: Merge TextSurface into FontSurface
NEVERHOOD: Clean up DiskplayerScene

- Enable return to launcher
- Remove obsolete comments
- Remove braces in single-line statements
- Remove unused non-transparent drawing code in BaseSurface::copyFrom
- Clean up mouse cursor insertion code in Scene class
NEVERHOOD: Add enum for the resource types
NEVERHOOD: Change graphic resource draw method to get a Surface instead of separate pixels/pitch

- Merge SpriteResource::load and load2
NEVERHOOD: Move Scene2804::initCrystalColors() to GameModule::initCrystalColorsPuzzle()

- Add Scene::isMessageList2, only used in Scene2101
NEVERHOOD: Remove obsolete TODOs
NEVERHOOD: Add tables for Scene2706
NEVERHOOD: Rework the car track scenes in Module2500 and Module2700

- Move findClosestTrack code from several scenes to new Tracks::findTrackPoint
- Remove const kScene2706 arrays and use it from the dat instead
NEVERHOOD: Remove more old TODOs
NEVERHOOD: Rename SceneInfo2700 to TrackInfo