Add a way to display shadow map.
Reverse shadowmap views.
Add wireframe frustrum view.
Fix build
Fix shadowdebug not using right viewfrustrum
Merge branch 'master' into shadowdebug
Removed unused variables.
Factorize transparent mesh rendering.
Remove code never executed.
Use a precomputed invmatrix in gi.frag

(General) matrix inversion is costly, it's better if it's done a single
time on cpu. Improve performance.
Merge branch 'master' of github.com:supertuxkart/stk-code
Tigher fit of shadow map.
Report opengl vendor and renderer.
Fix GI matrix generation.
Fix disappearing shadows
Use EAC_OFF
Merge remote-tracking branch 'origin/shadowdebug'
Merge branch 'master' of https://github.com/supertuxkart/stk-code
Implemented bilateral for compute path.
Some tweak to ssao.