Castle Game Engine: Mirrored Repeat mode, TextureProperties.BoundaryModeS/T/R support

Thanks to Matthias (Free Pascal meets SDL) we now support “mirrored repeat” mode for textures, for both glTF and X3D models. We also support X3D TTexturePropertiesNode.BoundaryModeS/T/R properties, which allow to request a wrapping mode — clamp, repeat, or mirrored repeat. (see TBoundaryMode) The way you would request it in Pascal is by creating and adjusting …