Compatibility update

This update brings compatibility with the newest version of my other plugin, BlueMapOfflinePlayerMarkers, and it should also be more stable in some extremely rare cases.
I also included my new Update Checker, so you'll be notified when this plugin has an update :)

_{Use the DEBUG version if you want to see more messages about what the plugin is up to. You can swap between the two versions freely.}

Full Changelog: v2.0.0...v3