Can't Disable Decayed Nature

[kosakriszi]

Hello, I'll start this off by saying that this seems similar to #24 but isn't quite the same.

I'm using a version I just compiled from the repo before I created this issue.

I'm trying to set IncludeDecayedNature to false, but every time I start the server it changes it back to true if the world type is Destroyed. This doesn't happen for any of the feature inclusion settings like IncludeMountains. I remember being able to have this setting defy the world style in a prior version, and would like to have it set up that way again.

[echurchill]

Some of the settings "sets" like Destroyed will force certain settings a particular way. I can't remember why I did that so long ago but am willing to revisit the decision.