* refactored FBoundingBox so that the game dependent members are global functions now.
* changed some methods of the model renderer to take a render style parameter instead of a full actor.
* made the portal state global, outside the framebuffer, because it is pure logic state without dependencies on the backend.
* took the setup functions out of FDynLightData - there is no need to have them as members and they age game dependent.
All decisions were done deep inside the texture creation code, leaving zero options to the higher level code for controlling the feature.
Changed this so that the option to upscale must be passed as a parameter to FRenderState::SetMaterial and extended all needed variables to manage the added texture variants.
Still not solved: Material layers need explicit control, not only for scaling but also for filtering.
