Follow up to my previous push. Changed demo client to read correct wss setting. Added error code

1) Forgot that the demo client read the wss setting for the 'info' command. Fixed that in respotify.py
2) respotify.py was also trying to use Event.get() rather than Event.wait()
3) Added error code 8 'Rate request error' - pretty sure this is correct, however it appears when trying to log in so I may be wrong. I got this from the js file on play.spotify.com. I'm happy to remove if needed.