Disc Jockey

This is a pretty big one. There have been many features added by EnderKill98. Here are a couple of the main changes:

• Much faster tuning (or next to none in some cases). Makes switching songs a lot faster
• Work under any client conditions (laggy, faster/slower client tps etc.)
• Add subcommand to change speed
• Add subcommand to view current song and it's progress/duration as timestamps
• Fix crashes they noticed when running the mod 24/7 (could also have been caused by their changes)

Again, many thanks to EnderKill98