etherpad and mumble updates

Hi there! =)

Sorry for putting both into one commit, I hope it's ok for you.

The etherpad update is quite crucial. I had pretty undefined behaviours before, the main change is that the node script is run directly in the supervisor service, not indirectly through the run.sh script. Now one can really stop the node process via the services pane (although the services pane does not display it properly, according to it the service would still be running after turning it off). 
Apart from that, etherpad does not run on my rPi, the load is to heavy. I hope it runs on the more powerful singleboard computers...

Cheers, -Heiner