[Mod compatibility] Distant Horizons support

[DerRoboMeister]

Iris Shaders recently updated to 1.7.0, introducing shader compatibility with Distant Horizons 2.1, a mod that adds LODs, or levels-of-detail rendering, to Minecraft. It would be a fun surprise to see DH compatibility added to Super Duper Vanilla shaders, but as of now, attempting to use it with DH results in the LODs being completely invisible.