Adopted convention name and value or values for WSF_VALUE and descendant (WSF_STRING ...)

kept `key' as redirection, and also string as obsolete redirection.
Router: provide a way to pass the request methods without using manifest string, thanks to WSF_ROUTER_METHODS
  so instead of using manifest array or manifest strings, just create an instance of WSF_ROUTER_METHODS
  for convenience, WSF_ROUTER provides a few `methods_...' returning prebuilt WSF_ROUTER_METHODS objects
Improved code related to unicode handling in URL, and parameters (before the framework was doing too much)

library/server/wsf/src/response/wsf_file_response.e

@@ -150,7 +150,7 @@ feature -- Element change
 			update_content_length
 		end
 
-feature {WSF_SERVICE, WSF_RESPONSE} -- Output
+feature {WSF_RESPONSE} -- Output
 
 	send_to (res: WSF_RESPONSE)
 		local