add tun class, and wonky integer get/set for IPv4 addr
add tun class, and wonky integer get/set for IPv4 addr

jncornett/libdnet,kbandla/libdnet,wtfbbqhax/libdnet,jncornett/libdnet,kbandla/libdnet,kbandla/libdnet,wtfbbqhax/libdnet,wtfbbqhax/libdnet,jncornett/libdnet