Turn 'premult' to False by default for fix 'particle domain' issue
Deduplicate code for SunSky models.
Clean up style code and improve readability.
Move tuples up to file.
Fix issue whit old 'premult'  value on particle domain render
Add EXP_BRANCH boolean option aim to improve the work on different's branchs.
Apply EXP_BRANCH option for SSS integrator and Translucent material
Some minor typo changes.