work around a problem leading to pitch black pixels near the horizon
attempt to fix unix build errors introduced with previous change
minor comment fix
Implemented persistent variables, to pass data between animation frames.
Improved render performance in scenes with many distance-based fading lights, by cutting off fading lights entirely at a certain distance.
The cutoff distance is computed automatically from light source parameters and global adc_bailout, but can be overridden individually by the new max_distance parameter in the light_source block.
preparing v1.37.0.0-beta.5
Merge branch 'release/v1.37.0.0-beta.5'