OpenSystemsDevelopment / qpdf

Expose functions to the C API to create new loggers and to setLogger
and getLogger for QPDF and QPDFJob.

Run this:

for i in  **/*.cc **/*.c **/*.h **/*.hh; do
  clang-format < $i >| $i.new && mv $i.new $i
done

This comment expands all tabs using an 8-character tab-width. You
should ignore this commit when using git blame or use git blame -w.

In the early days, I used to use tabs where possible for indentation,
since emacs did this automatically. In recent years, I have switched
to only using spaces, which means qpdf source code has been a mixture
of spaces and tabs. I have avoided cleaning this up because of not
wanting gratuitous whitespaces change to cloud the output of git
blame, but I changed my mind after discussing with users who view qpdf
source code in editors/IDEs that have other tab widths by default and
in light of the fact that I am planning to start applying automatic
code formatting soon.

Clarify that names are to appear in canonical form with PDF escaping
resolved when used in non-parsing QPDFObjectHandle APIs and their C
API counterparts. See https://github.com/qpdf/qpdf/discussions/625.

add qpdf_oh_new_binary_unicode_string and qpdf_oh_get_binary_utf8_value

Add methods isNameAndEquals, isDictionaryOfType, isStreamOfType

* Handle error conditions that occur when using the object handle
  interfaces. In the past, some exceptions were not correctly
  converted to errors or warnings.
* Add more detailed information to qpdf-c.h
* Make it possible to work more explicitly with uninitialized objects

Return new qpdf_oh from qpdf_oh_wrap_in_array when input is already an array.
Update some doc comments in qpdf-c.h.