Background music, and stereo sounds

• New: background music. Put playlists of your sounds in a music/ folder and they play to each player in the worlds, WorldGuard regions or areas you choose, or when you start them with /rp music play. Shuffle, loop, a gap between tracks and priorities for overlapping places are all settings, and Minecraft's own music stays quiet while yours plays. /rp music stop and /rp music skip each have their own permission, so players can be allowed to stop or skip without starting anything. Plugins can start and stop music through engine.music(). See Music.
• New: stereo sounds are supported and documented. A stereo file plays the same everywhere, which suits music and menu sounds; a mono file comes from a spot in the world and fades with distance. See Mono or stereo.
• New: /rp sound stop <id|all> [player] ends a sound early, and plugins can do the same with Sounds.stop.
• New: RP Engine reads each sound file's length itself, so looping vehicle sounds no longer need length:. /rp sounds shows each sound's length and whether it is mono or stereo.
• New: /rp reload warns about a vehicle sound that is a stereo file (it cannot come from the vehicle), and about a file that is not Ogg Vorbis, such as a renamed mp3, which would play as silence.