- Adopted deferred WGI_VALUE design for Result type of *_parameter and similar functions

- Adopted the ITERATION_CURSOR [WGI_VALUE] design for *_parameters and similar functions
- renamed parameter as item
- provided helper function to handle "string" value parameters

Experimental for now.

library/server/ewsgi/connectors/nino/src/ewf_nino_connector.e

@@ -78,7 +78,7 @@ feature -- Server
 		do
 			create req.make (env, create {EWF_NINO_INPUT_STREAM}.make (a_input))
 			create res.make (create {EWF_NINO_OUTPUT_STREAM}.make (a_output))
-			req.set_meta_variable ("RAW_HEADER_DATA", a_headers_text)
+			req.set_meta_string_variable ("RAW_HEADER_DATA", a_headers_text)
 			application.execute (req, res)
 		end