Ensure that PATH_INFO and REQUEST_URI are following the CGI specifications:

- PATH_INFO is percent decoded but still utf-8 encoded,
  this is available via WGI.path_info and WSF_REQUEST.utf_8_path_info.
- Added WSF_REQUEST.percent_encoded_path_info
- and WSF_REQUEST.path_info remains the unicode value for PATH_INFO

Added cgi_variables: WGI_REQUEST_CGI_VARIABLES to have a simple and quick view on CGI variables
Added execution_variables to be able to iterate on execution variables.
Added PERCENT_ENCODER.percent_decoded_utf_8_string
Improved the WSF_DEBUG_HANDLER to provide more information thanks to WSF_DEBUG_INFORMATION object.

library/server/ewsgi/src/implementation/wgi_request_from_table.e

@@ -319,6 +319,7 @@ feature {NONE} -- Element change: CGI meta parameter related to PATH_INFO
 			until
 				a_vars.after
 			loop
+					-- Warning: truncated value to ascii !!!
 				table.force (a_vars.item_for_iteration.to_string_8, a_vars.key_for_iteration)
 				a_vars.forth
 			end