268938a706
Fixes #1650. Mojang changed the biomes code so that it now can have different biomes for different Y levels. We need to adjust our logic accordingly, which is done through some small BiomeDispensary class where we shove a numpy'd Mojang array in and can then read out the biomes for each level. Biome data is now stored per-section, which needed some changes on the C side of things. I didn't change anything in the biome overlay code so I wouldn't be surprised if it's broken now, but for the time being I'd rather have 1.15 fixed than some obscure overlay. Tested to work with 1.14 and 1.15 data. No new biomes have been added to the code yet.