Added a range of new fun date strings to try. This set of dates come from a

mail posted to the http-state mailing list, from Adam Barth, and is said to be
the set of date formats the Chrome browser code is tested against:
http://www.ietf.org/mail-archive/web/http-state/current/msg00129.html

libcurl parses most of them identically, but not all of them.