Base normal map support has been implemented in path tracing (just geometry normal replacement).
Smooth normal adaptation has been implemeneted in order to avoid black areas artefacts during path tracing.
Tangent normal space calcuation has been moved to separate unified function.
Tangent space orthogonalization algorithm has been changed in order to handle all orientations and combinations of UV coordinates.
"Range" parameter of point light sources (positional and spot) concidering in PBR has been added.
Angular attenuation parameter of spot light in PBR has been reimplemented based on existing "concentration" parameter.
