Add numberformat internationalization features

[ronanft]

Is it possible to add support for decimal separators and thousand separators in numberformat?
suggested parameters:
decimals="."
thousands=","

Like:
"1.897,99" => European
"1,545.00" => US and UK

[xnimorz]

Hi! It's not implemented yet, but the idea is great.
I'm not sure I have enough time for that, but I'll glad to review and cut a new release with the feature