Improve soundtrack

[DCxDemo]

Current issues:

• pseudo random (random order is always the same)
• 25 songs limit

Suggestions:

• show artist and track name when new track plays
• custom soundtrack support (maybe generate automatically, like gta?)

[buvk]

I have a few suggestions as well:

• ability to bind a button to skip track
• option to prevent next track from being played when restarting a level