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/specification/request/wgi_request.e

@@ -88,6 +88,14 @@ feature -- Access: Input
 
 feature -- Access: CGI meta variables
 
+	cgi_variables: WGI_REQUEST_CGI_VARIABLES
+			-- Object containing the CGI variables
+			--| note: a new instance is created on each call!
+			--| this is mainly for debugging purpose.
+		do
+			create Result.make (Current)
+		end
+
 	meta_variable (a_name: READABLE_STRING_GENERAL): detachable READABLE_STRING_8
 			-- Environment variable related to `a_name'
 		require
@@ -297,6 +305,8 @@ feature -- Common Gateway Interface - 1.1       8 January 1996
 			-- The PATH_INFO value is case-sensitive, and the server MUST
 			-- preserve the case of the PATH_INFO element of the URI when
 			-- making it available to scripts.
+			--
+			-- Note: it is UTF-8 encoded, and percent decoded.
 		deferred
 		end