New BeEF injection module
* src/modules/attacks/__init__.py
  src/modules/attacks/beef_hook.py
  -- Injects BeEF hooks into ARPP traffic.  See wiki for more
  information about this.
* src/modules/attacks/attack.py
  -- Abstract attack
* src/lib/libmproxy
  -- A fantastic library, and something I've been dancing around adding.
  This library will come in handy for plenty of other future modules.
* src/modules/sniffer/packet_modifier.py
  -- Removed this module; too buggy, and should be rewritten without the
  use of nfqueue