use the svg <use> element to avoid exporting bitmaps more than once. With this document we were exporting the same image hundreds of times. Change-Id: I9c2501ce67c263720719bac3d801854b48740905 Reviewed-on: https://gerrit.libreoffice.org/c/core/+/194344 Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk> Tested-by: Jenkins