Little fixes:
 * make some module variables static to prevent name pollution
 * Add some comments to clarify what's going on and some XXXs to address
 * Add a space after "for" before (
 * exc_value and tb can be NULL in some cases
 * Get working on Windows (I think)
diff --git a/PC/config.c b/PC/config.c
index 1d142b56..0885cdc 100644
--- a/PC/config.c
+++ b/PC/config.c
@@ -68,6 +68,7 @@
 extern void init_lsprof(void);
 extern void init_ast(void);
 extern void init_types(void);
+extern void initatexit(void);
 
 /* tools/freeze/makeconfig.py marker for additional "extern" */
 /* -- ADDMODULE MARKER 1 -- */
@@ -79,6 +80,7 @@
 
         {"array", initarray},
 	{"_ast", init_ast},
+	{"atexit", initatexit},
 #ifdef MS_WINDOWS
 #ifndef MS_WIN64
         {"audioop", initaudioop},