Server: Steam in-house streaming

[GPMueller]

The following guide explains how to get steam running on a headless Arch Linux server such that it can be used for in-house streaming to another Linux device: https://steamcommunity.com/sharedfiles/filedetails/?id=680514371
I think this would be very cool, although it does not seem to work as nicely as it would using Windows devices.

[NOhs]

Definitely related to #54

[NOhs]

Maybe bundle all the steam stuff there?

[GPMueller]

I think this is probably another task after we got steam running at all. I'm not even sure yet if in-house streaming can be prepared properly by our installer or if this has to be done later by the user.