USE_TOOLS and any of "autoconf", "autoconf213", "automake" or
"automake14". Also, we don't need to call the auto* tools via
${ACLOCAL}, ${AUTOCONF}, etc., since the tools framework takes care
to symlink the correct tool to the correct name, so we can just use
aclocal, autoconf, etc.
The programme (two programmes really - but they're just links to each
other) converts 48x48x1 images to and from a compressed format. The
uncompressed images are expected to contain 48x48/4 (576) hex digits.
All other characters and any `0's followed by `X' or `x' are ignored.
Usually the files are 48 lines of "0x%04X,0x%04X,0x%04X,". The
compressed images contain some number of printable characters. Non
printable characters, including ` ' are ignored. The purpose of the
programme is to allow the inclusion of face images within mail headers
using the field name `X-face: '.
Submitted by Osamu OISHI <oishi@alef.ims.ac.jp> in PR 17541
