Add home.map (new first-level)

Lots of changes here to get this level working the way I wanted:

- Added fire sprite that hurts when touched

- Stopped scrolling at edges of map

- Added a new midi track for the level

- Added some new sounds, removed the prize-pickup sound (it clashed with
  the background music)

I also adjusted the volume levels on some of the sound effects, so that
the all the soudns have a more even volume. Before, some sounds were
much louder than others.