Pick up their copyright notice and additions.
Replace links used as references.
Our version is now their version with some additional comments and
different links (replacing broken links with non-broken ones).
Change-Id: I785d14f537abd96cd7baa3438191e1371e34ebc0
Reviewed-on: https://code.wireshark.org/review/21828
Reviewed-by: Guy Harris <guy@alum.mit.edu>