Initial use case is to avoid creating a whole Draw document + a poppler
process for each and every PDF image we load in a document.

The MSVC patch is only to support MSVC 2013, as upstream already moved
to MSVC 2015.

Change-Id: I3c9dbac3e3de9f2e874ca4cfec0a9dd8a388b87c
Reviewed-on: https://gerrit.libreoffice.org/34022Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>