* Fixes#486. Builds on code from Steffen Stundzig
- Switch from ICU4J to juniversalchardet
(Java port of Mozilla charset detector)
- Replace org.json code with Jackson
- Add tests
- Add TODO for multi-file character encoding mismatches
* Restore dependency lost in rebase
Co-authored-by: Steffen Stundzig <git@stundzig.de>