Start organizing WRAM

- Use db and dw when they're more meaningful than ds 1/2
- Use unions to group related labels

engine/specials.asm

@@ -618,9 +618,9 @@ SpecialGameboyCheck: ; c478
 
 Special_FadeOutMusic: ; c48f
 	ld a, MUSIC_NONE % $100
-	ld [MusicFadeIDLo], a
+	ld [MusicFadeID], a
 	ld a, MUSIC_NONE / $100
-	ld [MusicFadeIDHi], a
+	ld [MusicFadeID + 1], a
 	ld a, $2
 	ld [MusicFade], a
 	ret