Copyright for netcat source package in Huanghe V3.0

Netcat was created in the year 1995 and was developed until first
months of the 1996, when it reached version 1.10, released by Avian
Research (avian.org).

This is the traditional netcat,
    Copyright: © 1995-1996, Avian Research

The following permission statement is excerpted from `netcat.blurb':

  Netcat and the associated package is a product of Avian Research,
  and is freely available in full source form with no restrictions
  save an obligation to give credit where due.

There is also a development branch (called "GNU Netcat") available. It
was started by Giovanni Giacobbi , to improve
portability, usability and features design. Official project homepage:
http://netcat.sourceforge.net.