OpenSystemsDevelopment / qpdf

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.

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

Also fix QPDFArgParser

Move ArgParser from qpdf.cc into QPDFJob.cc. It still works with
millions of public member variables, but now qpdf.cc is minimal and
just calls stable library functions.

Convert remaining static functions that take QPDFJob& as a parameter
to member functions. Utility functions that don't take QPDFJob& remain
static functions and can probably just stay that way since the keep
extra complexity out of QPDFJob.hh.

Remove remaining temporary duplication of hard-coded values and direct
access to std::cout, std::cerr, and whoami in favor of parameters in
QPDFJob. This moves a few more static methods into QPDFJob member
functions.

Remove all calls to exit() from QPDFJob. Handle code that runs in
verbose mode to enable it to make use of output streams and message
prefix (whoami) from QPDFJob. This removes temporarily duplicated exit
code logic and most access to whoami/std::cout outside of QPDFJob
proper.