ofproto_v1_4: Add tun_ipv4_src and tun_ipv4_dst NXMs

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
sw test tool: Fix typos

Reported by Ian Y. Choi on ryu-devel.

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>