OpenSystemsDevelopment / qpdf

This results in measurable performance improvements to packaged binary
libqpdf distributions. QTC remains available for library users and is
still selectively enabled in CI.

Run this:

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

The Apache License version 2.0 is now the primary license for qpdf.
However, users may, at their option, continue to use Artistic version
2.0.

Also add copyright notice to a few public headers that were missing
one.

git-svn-id: svn+q:///qpdf/trunk@1051 71b93d88-0707-0410-a8cf-f5a4172ac649

git-svn-id: svn+q:///qpdf/trunk@935 71b93d88-0707-0410-a8cf-f5a4172ac649

git-svn-id: svn+q:///qpdf/trunk@851 71b93d88-0707-0410-a8cf-f5a4172ac649

… for C and C++ interfaces

git-svn-id: svn+q:///qpdf/trunk@828 71b93d88-0707-0410-a8cf-f5a4172ac649

git-svn-id: svn+q:///qpdf/trunk@688 71b93d88-0707-0410-a8cf-f5a4172ac649

git-svn-id: svn+q:///qpdf/trunk@644 71b93d88-0707-0410-a8cf-f5a4172ac649

git-svn-id: svn+q:///qpdf/trunk@599 71b93d88-0707-0410-a8cf-f5a4172ac649