Merge from vendor branch TNF:

Merge from vendor branch TNF:
Import tex-sepnum-2.0 as print/tex-sepnum.

Provides a command to print a number with (potentially different)
separators every three digits in the parts either side of the decimal
point (the point itself is also configurable). The macro is fully
expandable and not fragile (unless one of the separators is). There is
also a command \sepnumform, that may be used when defining \the<counter>
macros.