Add options.onError to handle errors

This was a two fold problem:
 - The data reader was not passing enough information to the fncError callback function it received. It was not using the fncError when making HEAD requests.
 - ID3 was never using the fncError callback error function provided by the dataReader.
Facilitate debugging with example/index.html
Change compiler.jar path to be local

I guess most people will just put it in the same folder.