tinymail.el: Adjust comment and delete aput (assoc.el no longer in Emacs)

Signed-off-by: Jari Aalto <jari.aalto@cante.net>
tiny/tinygnus.el: remove assoc.el
tiny/tinyliba.el: remove assoc.el
tiny/tinyliby.el: remove assoc.el
tiny/tinymail.el: remove assoc.el
tiny/tinypath.el: remove assoc.el
tiny/tinymy.el: remove assoc.el
tiny/tinyprocmail.el: remove assoc.el
tiny/tinyscroll.el: remove assoc.el
tiny/tinytf.el: remove assoc.el
ChangeLog: remove assoc.el