Try to put IA in its own thread
Revert "Try to put IA in its own thread"

This reverts commit 2a60a841556a9a6cdd3a259bebd44e95365f8f64.
Reenable billboards
Revert "Use a parallel loop for IA"

This reverts commit 8e333afa99cddf0a4092b780812baee42276d8ab.
Do not set glewExperimental outside of linux
Drop support for GL 3.1  on windows

Fixed pipeline will be used instead
Add a dtor to animated mesh
Use __linux__  macro
Block event for one-element ribbon widget in the same way as multi-element widget.

This fixes problem with pressing left and right arrow in track and GP info screen.
Filtering actions is not needed now
Delete sync object
Fix second texcoord in instanced_object_pass.vert
Fix snb on linux
Fixed compilation of font_tool.
Set texture matrix in updateNoGL and not in updateGL
Do not use kart position if there is no kart
Do not allow specvalue to be below 0.

Just in case it shouldnt be possible anyway.
Tweak fade-in/fade-out times in cutscenes and remove hardcoded values
Merge branch 'master' of https://github.com/supertuxkart/stk-code
Fix negative value inside tonemap

It should be checked before but since it's not always reproducible.