Add bin/list-https-ciphers to test an https server

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
bin/ping6-local: fix mac_to_ip6ll, tr table was wrong

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
bin/ping6-local: try ndisc6 before ping6 to avoid non-allocated link-local addresses

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>