OpenSystemsDevelopment / qpdf

Add copy_if_fallback and explain how it differs from copy_if_shared.

Modify QPDFParser::parse to call QPDF::getObject instead.

Part of #729

from "qpdf-v2" to "qpdf": [..., ...]

Move responsibility for creating shared pointers to objects and cloning from QPDFObjectHandle to QPDFObject.

* 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.

This is so it will fit on one line after a qtest upgrade allows us to
split lines.

add qpdf_oh_new_binary_unicode_string and qpdf_oh_get_binary_utf8_value

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.

Changing from bool requiring true to string requiring the empty string
is more consistent with the CLI and makes it possible to add an
optional parameter or choices later without breaking compatibility.

Move most of the methods called from qpdf.cc after argument parsing
into QPDFJob. In this increment, enough QPDFJob API has been added to
handle the branch of QPDFJob::run() that creates output with an
appropriate division between qpdf.cc and QPDFJob.

There are temporary bits of code to enable everything to compile and
pass the test suite, including some duplication and hard-coded values.

Add methods isNameAndEquals, isDictionaryOfType, isStreamOfType