OpenSystemsDevelopment / qpdf

Remove the name/number tree object helper constructors that don't take
a QPDF&.

Run this:

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

Create the typedefs directly in iterators rather than deriving from
the deprecated std::iterator class.

Keep a std::pair internal to the iterators so that operator* can
return a reference and operator-> can work, and each can work without
copying pairs of objects around.

Add constructors that take a QPDF object so we can issue warnings and
create new indirect objects.

Create a computationally and memory efficient implementation of name
and number trees that does binary searches as intended by the data
structure rather than loading into a map, which can use a great deal
of memory and can be very slow.