* Merge from Debian jessie, remaining changes:
  + d/p/sound-no-uaccess.patch
    - SteamOS uses a system-wide PulseAudio instance, which should be the
      only thing with access to the sound devices. As such,
      disable uaccess for sound devices.
  + d/p/pulse-owns-audio.patch
    - Change the sound device group from the default audio to pulse so that
      only the system-wide pulse daemon can access those devices.
  + streamcontroller-support.patch
    - Allow access by the steam group to uinput devices, as used for Steam
      Controller support