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/router/wsf_file_system_handler.e

@@ -67,7 +67,7 @@ feature -- Execution
 			-- i.e: path of the file system resource if any
 		do
 			if attached {WSF_STRING} ctx.item ("path") as v_path then
-				Result := v_path.string.as_string_8
+				Result := v_path.value.as_string_8
 			end
 		end