Add note about installing mplayer first?

[poshaughnessy]

Hi, when I ran node app.js on a Mac, I got:

Error: spawn mplayer ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:238:19)
...

I solved this by installing mplayer (with brew install mplayer). Perhaps it might be worth mentioning this in the README in case others might come across it too?

[ericpelland]

This was helpful, i figured I would check the one open issue before diagnosing. Thank you.

[SovGVD]

I'm really sorry. This project was mostly just for fun (and achieve some new skills and technology) and I'm not interested to continue with it (at least at that moment). I'm happy if anybody fork it and improve.