Removed any (put|write)_file_content from the WSF_ or WGI_ OUTPUT classes

Now DEFAULT_SERVICE has to be created instead of inherited.
   - This seems to be better for new user, and this avoid potential conflict and difference when inheriting between the various DEFAULT_SERVICE implementation.
   - remember that DEFAULT_SERVICE, is mainly to help the user to build its very first service.
Use READABLE_STRING_8 as argument whenever it is possible.
Added WSF_RESPONSE_MESSAGE, and WSF_RESPONSE.put_response (a_response_message)
Now WSF_RESPONSE inherit from WGI_RESPONSE

examples/restbucks/src/restbucks_server.e

@@ -14,17 +14,17 @@ inherit
 
 	ROUTED_SERVICE_HELPER
 
-	DEFAULT_SERVICE
-
 create
 	make
 
 feature {NONE} -- Initialization
 
 	make
+		local
+			s: DEFAULT_SERVICE
 		do
 			initialize_router
-			make_and_launch
+			create s.make_and_launch (agent execute)
 		end
 
 	create_router