The new emplacement method updates page objects in place without
generating new objgen numbers, meaning we no longer need to update the table
of contents to preserve links.
With the new pikepdf 1.2.0 we no longer need to hold file handles
open because of the "copy to memory" functionality. We retain
the behavior of closing/reopening the output PDF every 100 pages as
a way to limit memory usage.
If using --tesseract-timeout 0 and any image processing on a file with
more than 100 pages, the weave handoff will occur. Ensure this
works correctly even if no Glyphless font is present.
Closes#347
James R. Barlow