This branch is disjointed from the main branch and contains external libraries. It is primarily here so they can be reliably downloaded from Azure Pipelines.

curl -L https://www.ijg.org/files/jpegsrc.v9c.tar.gz -o jpegsrc.v9c.tar.gz
curl -L https://downloads.sourceforge.net/project/qpdf/external-libs/2017-08-21/qpdf-external-libs-bin.zip -o qpdf-external-libs-bin.zip