Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
Like the DSNLEXER header, this has visibility in over 700
files, whereas well under half actually use any of it
(quite a bit, but not all, of it actually via DSNLEXER)
Many places already forward-declare the OUTPUTFORMATTER type,
by doing that for the others, it still possible to use the
non-IO methods without having to see richio.h.
They don't define a KiCad string class, so the header file name was
somewhat misleading. But the fact that they didn't match definitely
made coding more difficult.