This adds exclusion bands around the sun’s exclusion zones of Bering, Omega-41, Tau-31 and Tau-23.
Those bands are using `cull_mode = 2` so only their sun-facing side is visible.
Also their fade distances was set up so they are mostly just visible when you are at the edge of the sun’s exclusion zones.
Same cull-mode and fade added for Tau-31 Harris exclusion band, too.
The Dust asteroid belt texture previously had an issue where it looked as if groups of rocks were glued together. They have been properly separated in this commit.
In the base game and JFLP, this entry is missing. Adding it enabled players to see the field from a far away distance instead of it just "popping" in when flying towards FP10.
The Harris exclusion zone is so big that you cannot see the
asteroid billboards anymore at the planet.
To still show that it is entirely surrounded, an asteroid
band as done at other places in the game gives the impression.
