* Add relative numbers for commands by prepending ~
* Some builtin code cleanup
* Disallow nan and inf in minetest.string_to_area
* Remove unused local variable teleportee (makes Luacheck happy)
* Clean up core.string_to_pos
* Make area parsing less permissive
* Rewrite tests as busted tests
* /time: Fix negative minutes not working
Co-authored-by: Lars Mueller <appgurulars@gmx.de>