New version + open source release

It took me a year and a half, but I finally got around to cleaning up the source code for Lonely Star, and it's now open-sourced on GitHub!

While I was at it, I took the opportunity to make a few tweaks and published a new version of the game. Here's the changelog:

• Improved the UI for lives
• Added a score display in-game and removed the score from the title bar
• Fixed a bug with the star's trail being too long, and made it a little prettier.