- package is now null-safety
- remove dart:io - more web compatibility
- remove dart:isolate - so it's compatible with web
- add new LatLng class for location
- fix location parsing from cartridge
- process data within an isolate
- code cleanup
- remove unused dependencies
It's a partial port of https://github.com/mars3142/wherugo, so everyone can decode Wherigo Cartridges.