Use get() and use_count() instead. Add #define
NO_POINTERHOLDER_DEPRECATION to remove deprecation markers for these
only.
This commit also removes all deprecated PointerHolder API calls from
qpdf's code except in PointerHolder's test suite, which must continue
to test the deprecated APIs.
For optional parameter/choices, generate an overloaded config method
that takes no arguments. This makes it possible to convert from a bare
argument to one that takes an optional parameter without breaking
binary compatibility.
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.
Why? The main methods that create them return smart pointers so that
users can initialize them when needed, which you can't do with
references. Returning pointers instead of references makes for a more
uniform interface.
Create QPDFJob_options.cc to hold API implementation functions.
Reorganize a little in preparation for moving public member variables
private and creating the real QPDFJob API that will be used by callers
as well as the argv/json initialization methods.
