Outdated documentation on -lang argument?

I encountered "Unsupported language: en" error when I was trying to run the `TokenNameFinderConverter` or the `TokenNameFinderTrainer`.

I'm not sure if I understood the bug correctly but it seems that after 2 hours of trying, I found out that apparently in a certain version after `1.5.3`, OpenNLP changed the language codes from two characters to three characters, i.e. one should have passed in `eng` instead of `en`. But the documentation was never updated on this and no meaningful error message was given (i.e. the program didn't suggest "supported languages" instead).