Now with ATI driver support (and bugfixes)

Changes from v1.1:

• Added support for steambox_ati: a SteamOS image with proprietary ATI/AMD drivers
• Fixed a bug in util/steambox that prevented some Pulse Audio sound from streaming
• util/steambox now prints an error if ${STEAMUSER_HOME} is unset
• Documentation improvements
• Dockerfile supportability improvements

Thanks to @jcorrado for bug fixes!

Hardware accelerated video support added

Changes from v1.0

• steambox.sh is now just called steambox
• steambox image now includes the SteamOS firmware-linux-free package
• steambox command now shares your /dev/dri devices for hardware accelerated video support
• Can now use the environment variable ${DOCKER} to run docker in different ways, (e.g. DOCKER="sudo docker")

Steam client launches with audio and video support.

Audio/video access provided via util/steambox.sh script, which is a low-security solution.

Container has unfettered access to /dev/shm, /var/lib/dbus, /dev/snd, /tmp/.X11-unix,
/run/user/<id>/pulse, and ~/.pulse

It can also read /etc/machine-id directly.

First stable version

Successfully builds a SteamOS Brewmaster image that is able to launch a bash shell.

Have not yet attempted to run the steam-launcher.