Things which have not yet been done for this release but which I will
hopefully have done before one of the next releases:

  - routine which prepares incompletely decoded images for Xlib

  - call-back function which allows to implement a graphical progress meter

  - use more efficient resolution reduction code suggested by
    Dr. Klaus Bartz <bartzkau@kou3.ina.de>

  - investigate whether there is a standard way of embedding JBIG
    into TIFF and implement it (see also RFC 2301)

  - ITU-T T.85 compatibility (this means supporting files with
    Y_D = 0xffffffff, L_D = 0xffffffff, and MX = 127)