The negociation with the server can be very strange becuase servers
can lie and because it isn't always clear what to do.  

	When something starts to require payment 
	(generally warn because people will probably want to switch
	their links over to a free source of the same information)

	When something says unauthorised
	(some servers don't like to say which is which)

As for the rest, I'm not too sure what all of them mean.. 


	       100 => 'Continue',
	       101 => 'Switching Protocols',
pass	       200 => 'OK',
pass	       201 => 'Created',
pass (strange) 202 => 'Accepted',
pass (warn?)   203 => 'Non-Authoritative Information',
fail	       204 => 'No Content',
pass	       205 => 'Reset Content',
pass	       206 => 'Partial Content',
pass	       300 => 'Multiple Choices',
redirect       301 => 'Moved Permanently',
pass (warn?)   302 => 'Moved Temporarily',
redirect       303 => 'See Other',
pass (strange) 304 => 'Not Modified',
pass (warn)    305 => 'Use Proxy',
fail	       400 => 'Bad Request',
fail (warn)    401 => 'Unauthorized',
fail/ (warn)   402 => 'Payment Required',
fail	       403 => 'Forbidden',
fail	       404 => 'Not Found',
fail	       405 => 'Method Not Allowed',
fail	       406 => 'Not Acceptable',
fail?	       407 => 'Proxy Authentication Required',
retry->fail    408 => 'Request Timeout',
fail?	       409 => 'Conflict',
fail?	       410 => 'Gone',
fail	       411 => 'Length Required',
fail	       412 => 'Precondition Failed',
fail	       413 => 'Request Entity Too Large',
fail	       414 => 'Request-URI Too Large',
pass (warn)    415 => 'Unsupported Media Type',
fail (warn)    500 => 'Internal Server Error',
fail (warn)    501 => 'Not Implemented',
fail? (warn)   502 => 'Bad Gateway',
fail->retry?   503 => 'Service Unavailable',  #can mean too busy??
fail	       504 => 'Gateway Timeout',
fail (warn)    505 => 'HTTP Version Not Supported',

