Add query parameter support

Socket.IO can use query parameters.
For example:

    io.connect("http://host.name/?app=appid");

The code access to ```http://host.name/socket.io/1/?app=appid``` on handshaking.
You can find the implementation in [socket.io.js#L178](https://github.com/Automattic/socket.io-client/blob/98c1bc84965320c9402bda4a07cfe9f46605323a/lib/io.js#L178)

I want to use this feature from ```ruby-socket.io-client-simple``` too.