When a kart has crashed, make the impulsive force a little more realistic. (depending on the kart velocity).
Convert texture from srgb and use srgb fbo
Expand HDR use.
Use utils function for renderbloom/blend
Clean skybox handling
Fix negative value that introduces a bug on nvidia
Remove some unused code
Improve ao and bloom.
Factorize luminance computation.
Write a shader to convert CIE to RGB.
Add some code to average log luminance.
Plug in brightness adaptation
Improve bright attenuation although not perfect
Using formula from an article suggested by samuncle
Disable auto exposure for now.
Merge branch 'properlinearpipeline'

* properlinearpipeline:
  Disable auto exposure for now.
  Using formula from an article suggested by samuncle
  Improve bright attenuation although not perfect
  Plug in brightness adaptation
  Add some code to average log luminance.
  Write a shader to convert CIE to RGB.
  Factorize luminance computation.
  Improve ao and bloom.
  Remove some unused code
  Fix negative value that introduces a bug on nvidia
  Expand HDR use.
  Convert texture from srgb and use srgb fbo
reenable diffuse env map
Instancing: Add support for scale transformation.
Actually enable scale.
Add support for alpha ref instancied materials.