361.28-0ubuntu1 breaks steam games due to move to GLVND

[Dave Chiluk]

Attempting to run a steam game under Xenial makes steam return the following error prompt.
"Could not find required OpenGL entry point 'glGetError'! Either your video card is unsupported, or your OpenGL driver needs to be updated.

Valve Steam thread
https://github.com/ValveSoftware/Counter-Strike-Global-Offensive/issues/610

I can confirm that the workaround
__GLVND_DISALLOW_PATCHING=1
Does workaround the issue.

https://devtalk.nvidia.com/default/topic/915640/unix-graphics-announcements-and-news/multiple-glx-client-libraries-in-the-nvidia-linux-driver-installer-package/

I'm not sure what the proper course of action should be for this, as Valve should probably fix this, but it might also affect other OpenGL applications.

Additionally it is being reported that newer drivers resolve this issue, but I'm not sure if that's purely due to a change in the defaults.