I decided that it's actually fine to copy a direct object to another
QPDF. Even if we eventually prevent a QPDFObject from having multiple
parents, this could happen if an object is moved.
On destruction of the QPDF object replace all indirect object references
with direct nulls.
Remove all existing code to release resolved references.
Fixes performance issue due to interaction of resetting QPDFValue::qpdf and
og members and prior code.
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.