OpenSystemsDevelopment / qpdf

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.

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.

When there is no context for writing output or error messages, use the
default logger.

* Replace --create-from-json=file with --json-input, which causes the
  regular input to be treated as json.
* Eliminate --to-json
* In --json=2, bring back "objects" and eliminate "objectinfo". Stream
  data is never present.
* In --json-output=2, write "qpdf-v2" with "objects" and include
  stream data.

Also add stubs for top-level QPDF methods (createFromJSON,
updateFromJSON)

Change .clang-format and commit automated changes from a fresh run of
format-code

Run this:

for i in  **/*.cc **/*.c **/*.h **/*.hh; do
  clang-format < $i >| $i.new && mv $i.new $i
done

This was unintended behavior that was added back for backward
compatibility. It is intentionally undocumented.

Let argv be a null-terminated array. There is already code that
assumes this, and it makes it easier to construct the arguments.

This makes it much more convention to use the initializeFromArgv
functions since you can use string literals.

All the coverage cases that used to be in qpdf.cc are now in
QPDFJob*.cc. It doesn't really matter, but better to follow the
convention of starting with the class that includes the coverage call.

Use "file" consistently for specifying a file path. We use "filename"
when adding attachments for a completely different purpose.

Use named functions rather than just end() for clarity.

All that's left now is input and output handling.