Decimal mark appropriate to language

Most continental European and South American countries use a comma for
the decimal mark.

The USA, Ireland, China, Japan etc. use a period for the decimal mark.

Regarding the Spanish language:
* Spain, Argentina, Chile etc. use a comma.
* Mexico, Guatemala, Peru etc. use a period.

We will deal with thes more specific subtleties of Spanish, as well as
other languages, in the future.