The check for GL_ARB_geometry_shader4 doesn't have sense at all because we don't use this extension and our geometry shaders use functionality which is available in core OpenGL 3.2.
The reason that it wasn't working for older mesa versions must be a bug in mesa or maybe missing other functionality (but not GL_ARB_geometry_shader4).
I checked it with mesa 11.2 and current git version and it works fine on intel, nouveau and with software rendering.
It needs some testing because it potentially affects all drivers with OpenGL >= 3.2 on every platform.
If someone could test it with Radeon drivers, I would be really happy to enable it in upcoming release, at least on linux.
- Increase version for sRGB-capable visual workaround because it doesn't look that it will be fixed anytime soon
- Enable compute shaders because it works fine now
- Enable texture compression because it works now too.
Texture compression for intel should work fine also for older versions, but it's hard to say which one version is the first working one.
