Implemented WSF_RESPONSE.put_error (...) and related

Added WSF_RESPONSE.put_character
Renamed  WGI_OUTPUT_STREAM.put_character_8 as put_character  to follow style of put_string  (and not put_string_8)
Refactored the WSF_DEFAULT_SERVICE_LAUNCHER
Added WSF_DEFAULT_SERVICE to be more user friendly
Splitted the wsf/default/ libraries to have wsf/connector/... and being able to handle more than one connector in the same application

library/server/ewsgi/specification/response/wgi_response.e

@@ -96,6 +96,13 @@ feature -- Header output operation
 
 feature -- Output operation
 
+	put_character (c: CHARACTER_8)
+			-- Send the character `c'
+		require
+			message_writable: message_writable
+		deferred
+		end
+
 	put_string (s: READABLE_STRING_8)
 			-- Send the string `s'
 		require
@@ -115,6 +122,14 @@ feature -- Output operation
 		deferred
 		end
 
+feature -- Error reporting
+
+	put_error (a_message: READABLE_STRING_8)
+			-- Report error described by `a_message'
+			-- This might be used by the underlying connector
+		deferred
+		end
+
 note
 	copyright: "2011-2012, Jocelyn Fiat, Javier Velilla, Eiffel Software and others"
 	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"