ip: add support of 'ip link type ip6tnl'

This patch allows to manage ip6 tunnels via the interface ip link.
The syntax for parameters is the same that 'ip -6 tunnel'.

It also allows to display tunnels parameters with 'ip -details link' or
'ip -details monitor link'.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
7 files changed