Pictures in templates and data that are BMP or TIFF were left out with a
warning. They are now recognised by their signature, sized from their
headers, and decoded through the same bounded reader as GIF (first page
of a TIFF). A BMP needs a valid info-header size after "BM", so text
starting with those two letters is still not taken for one.
A BMP or TIFF chosen for an XFA image field is kept in the data as
image/bmp or image/tiff, since the layout can now show it.