Audio muting, level 3 state, early animations, Newgrounds API.

- Muting the sound now stops all actively playing sounds.
- Slight changes to the collision detection for the actors due to
sprites having their pivots in the centre.
- End level state can now properly cycle between all 3 levels.
- The player and Hitler now both have early animations.
- Hooked up the Newgrounds API for connecting to scoreboards.
- Leaving TODO lists in comments for clean up.
- XML Manager generates XML entry for level 3.