Fixing the viewer count

These changes should fix the following issue:
https://github.com/StateOfTheArt89/Twitch.tv-on-XBMC/issues/37

Basically, Twitch has an inconsistent API when it comes to the viewer counts. In the call for featured streams, they pass it in with the Channel element. But everywhere else it is one level above that... 

I tested that is works on my RaspBMC.