OpenSystemsDevelopment / qpdf

When the schema wants a variable-length array, allow a single item as
well as allowing an array.

Remove any ambiguity around whether old or new value is being
returned.

This includes the output PDF, streams from --show-object and
attachments from --save-attachment. This also enables --verbose and
--progress to work with saving to stdout.

These mean to leave the original values alone. This is needed for
reconstructing streams from JSON given that the stream data and stream
dictionary may appear in any order in the JSON.

I decided these were confusing and inconsistent with how JSON works.
They muddle the API rather than improving it.

This reverts commit dc059560e73e0b373a6e54e71b07e3af4b692cb4.

I changed my mind. There's no harm in leaving it deprecated for a
release cycle.

See ChangeLog for rationale for not deprecating it as originally
planned.