OpenSystemsDevelopment / qpdf

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.

Also, reject them in strings.

Handle all incomplete token type errors in tokenError.

(except '\\' and '\uXXXX')