Maybe with the mapping, the line is a little bit too long. What do you think?

• lock and unlock merged to setLocked
• message.js simplifield
• tracks object created by message.js
• notification pass boolean instead int, as suggested

New functions:

• rename cheat case to playCustomTracks
• rename notification to a previous one (play-custom-tracks)

• space after if
• rename play-custom-tracks to playCustomTracks in the notification

And here is the converted track

• Custom track list
• Change type to play-custom-tracks
• Custom track comes from cheat
• Reorder my entry at contributors