updated to socket.io version 2

[chrisnew]

I quickly updated to socket.io version 2.0.3 as I encountered compatibility issues with most recent versions of Node in the policyfile dependency of socket.io 0.9.

Although it is working on my system now, please check if everything looks good. I found no solution to set the browser client minification as well as browser client etag like with socket.io version 0.9.x.

Cheers