Update TODO file

Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Replace COPYING link with a real file.

The link was pointing to automake-1.12 GPL licence, so it that version
of automake was absent the link was broken.
Problem reported by Frank Noack <fgroups@onlinehome.de>

Signed-off-by: Przemo Firszt <przemo@firszt.eu>