Biome Replacer

• Reworked biome replacement code. This should be unnoticeable, but it will prevent rules-not-loading type of bugs from happening again in the future.
• Log messages are now a bit more informative
• Added functionality for removing biomes (instead of replacing them)

Biome removal is a potentially unstable feature. It can mess up biome distribution, or even cause crashes. Please test thoroughly before using it in a world you care about!
You can remove a biome using a "null" keyword:

minecraft:desert > null