Fixed seeding problem where villages sometimes don't spawn with some world seeds
The plugin now runs with the updated spigot worldgen API (integration yet to be made, for now it just works. Works to integrate the new API may be done after mansions depending on what happens next)
Changed mob spawning code to bukkit API for block populator if called from PopulatorDataPostGen
Decreased default number of shipwrecks per mega chunk
Fixed issue in 1.15 where villages could not generate