Special thanks to Pixelmon Harmony for commissioning this plugin, and allowing it to be publically released.
Skeleton Horses in Vanilla & Sponge Powered servers bypass the default mob spawning gamerules.
Horses are additionally considered non-hostile mobs, so can wreck havoc with protection plugins.
This plugin has 2 mechanics.
The first is that when the gamerule doMobSpawning = false, Skeleton horses will no longer spawn naturally on lightning strikes.
Secondly, it introduces a new gamerule, removeSkeletalHorse.
removeSkeletalHorse = true will remove all skeletal horses & their passengers when the chunks load.
To enable, do /gamerule removeSkeletalHorse true
API 4, 4.1, 5 -> V1.0.0
API 6 -> V1.1.0