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
Calling wxDialog::EndModal() directly from inside the dialog is a
potential bug if the dialog is shown in the modeless or window modal
(quasi-modal). Use the internal button events where possible and
check for the appropriate mode before calling the correct end dialog
function.
