Minor.
Bugfix: we need to have DepthMask and ColorMask both fully on when clearing the FBO in Nodes!
Bug fix in RenderState.
Make it possible to render each DistortedNode with adjustable OpeGL state (writeing to Color, Depth,Stencil buffers, DEPTH, STENCIL, BLENDING on.off, etc)
New 'RenderState' class which will be used to change OpenGL state when rendering Nodes.