OpenSystemsDevelopment / qpdf

Warn if catalog type entry is invalid (fixes #810)

Improve --optimize-images to find images nested within XObjects

Refactor QdfFixer::processLines

Remove redundant parameter depth from QPDF::updateObjectMaps

Add new data member QPDFWriter::Members::root_og

Also, uninitialize QPDFWriter::Members members.

Also, change QPDFJob to use unique_ptr<QPDF> instead of shared pointers.

At the end of importing a JSON file, scan the object cache for reserved
objects and replace with null objects.

Recognise that JSON objects are effectively shared pointers to JSON_value.

Refactor setting of object descriptions in QPDF::JSONReactor

Refactor creation of object descriptions

Eliminate the use of shared pointers in JSONParser

Allow access to private header files when defining data members.

Also, name the type QPDFValue::Description.

Reduce boilerplate and increase efficiency by avoiding setting and
branching on action and ready in getToken.