Bukkit vs Spigot

I've been running a spigot Minecraft server for some time now, and developing plugins for it as well. I am confused about this Bukkit/Spigot thing. What is the difference between Bukkit and Spigot?

In my server folder, there is a spigot.yml and a bukkit.yml. Both seem to contain important settings. I am trying to write a world management plugin and I saw a post from someone else confused similarly. In it, the reply stated that bukkit.yml applies to the entire server and every world in it, while spigot.yml is per-world. However, in bukkit.yml there is an "allow-end" option. In server.properties there is an "allow-nether" option. In addition, neither server.properties, spigot.yml, nor bukkit.yml seem to have any settings in common. How can I change bukkit.yml settings per-world, and is there an easier way to manage all these setting for the server?

 

How should I manage the different config files and settings within per world?

 

Yes -- as I mentioned, I'm writing a world management mod, and many of the settings contained within bukkit.yml, spigot.yml, and server.properties seem to be settings that I would like to have per world. For instance, the "ticks-per.animal-spawns" in bukkit.yml would be a setting that a proper world management tool would regulate. The settings for everything seems to be very disjointed. Heck, even the allow-nether and allow-end settings are in server.properties and bukkit.yml. How can I properly regulate all of the different settings both per-world and as a whole?

 

I've been using the WorldCreator Object for a while now, but it does not have anywhere near the in-depth settings control that I need. The only methods that the object provides are the methods for:
- Changing the biome provider for the world
- Changing the world environment
- Changing whether the wold will generate structures
- Changing the chunk generator
- Changing if the world is hardcore or not
- Changing the seed
- Changing the type of world

These are pretty simple settings, but still useful. However, I need more control of the world generation/loading.
If you look at bukkit.yml you get much more in-depth settings such as:
- spawn limits for every type of mob
- spawning rates for every type of mob
- ticks per garbage collection per chunk

Is there a way to change these settings, and if not change them, override them while creating/loading a world?

 

Any suggestion on how to do that? There must be a better way than "hacking" into whatever is reading the file, right?

If not, thanks for your help, I appreciate it.