Create nl-NL-g0.ctb

Netherlands Grade 0
Create nl-NL-g0-chardefs.cti
Create nl-NL-g0-translation.cti
Convert the doctest for Dutch to a harness test
Integrate the nl-BE-translation.ctb module into nl-BE-g1.ctb

do the same for nl-NL-g0-translation.ctb and nl-NL-g0.ctb
Rename nl-NL-g0 to nl-NL-g1

in order to be consistent (Belgian table is also g1)
Delete old nl-be-g1.utb and Nl-Nl-g1.utb tables
Add Henri Apperloo to AUTHORS and update copyright notice
Explain differences between nl-BE-chardefs.cti and nl-NL-chardefs.cti

The goal is to eventually merge the two tables.

Also explain multipass rules in nl-NL-g1.ctb
Add NEWS entry
Merge branch 'tables/dutch'