Fix some typos and improve logging in test

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
Forward IPv6 NDP, work still in progress

Signed-off-by: Nicolas Iooss <nicolas.iooss_git@polytechnique.org>
Forward Router Advertisements with right options

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