keygen music play button per Mykhailo Onikiienko

Click extension button to play awesome 8-bit chiptune music. Click again to stop.
It's all.

This extension just streams music from keygenmusic.tk (collection of chiptune music from keygens).
Music is absolutely free and legal. Visit keygenmusic.tk for details.

Tip:
- Double-click on extension icon to play next track
- Hold cursor on extension button when music stopped. You'll see Total Played statistic.
This feature implemented in v1.1 so there is no info about played time before this update.

Source code https://github.com/onikienko/keygenjukebox-play-button