You can clone with
HTTPS or Subversion.
This is a cool project! Whats the deal with audio streaming though? What needs to be done to get that to work. I'm keen to help.
Hit me up
There's a separate project shairport that provides audio streaming. Technically this could be integrated in Airplayer, but I'm no longer actively maintaining this project so I'm not going to do that. If you would like to, feel free to fork and go ahead :)