Add libusipp 2.24

usi++ (UNIX Socket Interface) is a low-level network-library for
sending/receiving IP, IP6, ARP etc. packets directly on RAW or PACKET sockets.
It can also be used for network-monitoring and rapid development of pentesting
tools. It requires libpcap and libdnet if you want the Layer2 DNET provider.

WWW: https://github.com/stealth/libusipp