packet lib: add ipv6 support

Signed-off-by: "Henkel, Michael" <michael.henkel@hp.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: add ipv6 ICMP support

Signed-off-by: "Henkel, Michael" <michael.henkel@hp.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>