OpenSystemsDevelopment / qpdf

Reported by Stephane Chazelas. Potentially sensitive arguments could
be leaked to the environment during completion computation.

Thanks to github user @cdosborn for the basic enhancement.

... to remove the /Root /StructTreeRoot and /MarkInfo entries.

This requires a special build option.

(So folks working offline won't go for hours dreaming they can overlay *.txt files, until after the finish writing the txt file, and try it, and it doesn't work.)

Accept --file and --range as named parameters in additional to
allowing positional arguments. This is in preparation for adding
additional flags.

This commit contains only the manual changes. It is separated for
clarity. This commit would not pass CI because it lacks the automated
changes, which appear in the next commit.

Rather than adding yet another flag that is almost never useful on its
own, just have --remove-restrictions disable digital signatures. The
operations are still separate in the API.

Positional arguments are supported in a backward-compatible way, but
completion no longer guides users to it.

Add the command-line arguments. They don't do anything yet.

To reference another command line option description, `:qpdf:ref:` is needed instead of `:qpdf:option:` which is not resolved properly in the HTML documentation.

Avd xcsv brvtns.

Now --json-output just changes defaults. Allow output file with --json.

Add additional parameters that will be needed to call QPDF::writeJSON
in partial mode.