Add glDrawElementsIndirect support
Check for draw indirect support
Remove instancing
Increase instance buffer size
Gather object in instanced calls
Remove manual LOD code, it's now automatic
Fix crash with RSM
Remove stkinstancedscenenode.h/cpp
Use Irrlicht culling function
Fix poly counter with OpenMP
Fix culling
Fix culling of solid node for good
Use more aggressive culling.
Merge branch 'scenemanager-optimisation'