Use variadic function to load shader
Factorize EncodeNormal from Pass1 shaders.
Factorize DecodeNormal from misc shaders.
Factorize getLightFactor
Add missing utils/log.hpp in glwrap.hpp
Merge branch 'master' of https://github.com/supertuxkart/stk-code
Merge pull request #1252 from mcsab/master

Reset-per-lap achievement support
Some drivers dont support const array
Add a function to query supported glsl ver
Do not build shadow shader without gs support.
Merge commit 'f3e2da881a4d394c4ca902548e788f5b4c0bdd81'

* commit 'f3e2da881a4d394c4ca902548e788f5b4c0bdd81':
  Do not build shadow shader without gs support.
  Add a function to query supported glsl ver
  Some drivers dont support const array
Definitively fix stencil bug thx to graphitemaster from irc
SkyShader: attrib position is not always 0.
Add file path when a compiler error arise.
Fix a  shader compile failure on nvidia.
Factorise cubevbo/vao in shader.cpp
Do not render billboard outside of transparent pass
GPUParticles: some factorisation
Add an overload for draw2DImage with a single color
Use new single-color overload in font where possible