First cut at thread support libwww

Krishna Vedati wrote this extension to the thread module some time ago - I
think it is a great start so let's start discussing how this can be
implemented for real!

Krishna let me know he is on vacation until March 1st so don't expect
answers from him until then :)

Henrik

--
Henrik Frystyk Nielsen,
World Wide Web Consortium
http://www.w3.org/People/Frystyk