Inverted tiffs and multi-page tiff files

[Fred Jan Kraan]

While trying to get the bookmarks option work for me, I discovered
different behaviour of Tumble (0.33) for single page tiff files and
multi page tiff files.

The default behaviour if Tumble is to copy multi page tiffs as-is to the
pdf, but invert single page tiff files. If the last argument of the
pdf_write_g4_fax_image function in tumble_tiff.c (line 330-336) is
inverted, so is the behaviour; single page tiff files are ok, multiple
page tiff files are inverted (black/white).

Fred Jan