Bump version to 2.1.1

Disable custom explosions by default

Restore default config if missing

Initial changes for 3rd-party API

Fix Weeping Vine check crashing versions <1.16, restructure server ve…

…rsion info in constants, bump version

Fix edgecase in vines, update config and Readme

Increase calculated boundaries by one to improve merging in some cases

Improve extended piston replacement

Increase explode EventPriority to improve compatibility

This should resolve issues with WorldGuard

Bump version