bug#47103: numfmt: invalid suffix 'k'

[Sven Köhler]

Not only --from=si is broken. Also --to=si is broken:

$ numfmt --to=si 3000
3,0K

In order to not break backwards compatibility, you probably have to 
introduce a switch --lowercase-kilo such that --to=si produces proper SI 
compliant output. Then have --from=si accept both uppercase and lowercase k.

I have to say, that uppercause K is quite common, but it is not correct 
as far as SI prefixes are concerned.

Also note that Ki in iec-i mode is quite correct. I'm torn about iec 
mode. I believe that people silently switch 1000 for 1024 and use the 
lower case k as well as uppercase K. Maybe numfmt should have an option 
to accept/produce both here as well?

Is there really a standard/specification that allows k/K for 1024? 
Wikipedia only lists Ki as IEC prefixes.