emit transport-state and volume

Fiddling around with your Sonos Discovery. Great Stuff!
This commit is just a small change to emit the transport-state and volume notifications so the (html) client can catch them.

I forked your HTML client also.
My main goals for the fork are:
- to complete the basic functionallity
- to make it work on mobile browsers
- add a "play URL" function so I can just throw stuff at Sonos
- maybe add some voice recorgnition or text to speech stuff (would work only in Chrome)  (maybe a button that would speak the title of the current track - a recurring feature request from my friends)

I you don't want to be bothered with pull request - just ignore me or tell me to F Off.

regards!
Steffest