v5.3.0 - Full 1.21 Support & Navigation Algorithm Changes

Hey guys,
first of all, all dependencies have been updated to 1.21. Please create an issue if you experience any bugs!

Thanks to @MomoPewpew for making a very precise bug report in #82, which has now been fixed/optimized.
And also thank you @MomoPewpew for the pull request to fix premature path ending in #81

Full Changelog: v5.2.0...v5.3.0