Gumbo HTML parser THANKS file

Gumbo was originally written by Jonathan Tang, but many people helped out through suggestions, question-answering, code reviews, bugfixes, and organizational support.  Here is a list of these people.  Help me keep it complete and exempt of errors.

Adam Barth
Constantinos Michael
Ian Hickson
Jonathan Shneier
Mason Tang
Neal Norwitz
Othar Hansson
Stefan Haustein
Steffen Meschkat
