Apply two changes, systematically:

(1) Use PyErr_NewException("module.class", NULL, NULL) to create the
    exception object.

(2) Remove all calls to Py_FatalError(); instead, return or
    ignore the errors -- the import code now checks PyErr_Occurred()
    after calling a module's init function, so it's no longer a
    fatal error for the initialization to fail.

Also did some small cleanups, e.g. removed unnecessary test for
"already initialized" from initfpectl(), and unified
initposix()/initnt().

I haven't checked this very thoroughly, so while the changes are
pretty trivial -- beware of untested code!

Modules/regexmodule.c

@@ -718,7 +718,7 @@ initregex()
 	d = PyModule_GetDict(m);
 	
 	/* Initialize regex.error exception */
-	v = RegexError = PyString_FromString("regex.error");
+	v = RegexError = PyErr_NewException("regex.error", NULL, NULL);
 	if (v == NULL || PyDict_SetItemString(d, "error", v) != 0)
 		goto finally;
 	
@@ -742,5 +742,5 @@ initregex()
 	if (!PyErr_Occurred())
 		return;
   finally:
-	Py_FatalError("can't initialize regex module");
+	/* Nothing */ ;
 }