This patch supports "Image or Movie" and "Environment map" types of world texture for the viewport.
- "View", "AngMap" and "Equirectangular" types of mapping.
- Different types of texture blending (according to BI world render).
- Same color blending as when it lacked textures (but render via glsl).
Original author: @Dontsov Valentin (valentin_b4w)
Alexander (Blend4Web Team).