This reverts r63675 based on the discussion in this thread:

 http://mail.python.org/pipermail/python-dev/2008-June/079988.html

Python 2.6 should stick with PyString_* in its codebase.  The PyBytes_* names
in the spirit of 3.0 are available via a #define only.  See the email thread.
diff --git a/Include/pyerrors.h b/Include/pyerrors.h
index cdc9b76..a4233c9 100644
--- a/Include/pyerrors.h
+++ b/Include/pyerrors.h
@@ -104,7 +104,7 @@
 
 #define PyExceptionClass_Name(x)				   \
 	(PyClass_Check((x))					   \
-	 ? PyBytes_AS_STRING(((PyClassObject*)(x))->cl_name)	   \
+	 ? PyString_AS_STRING(((PyClassObject*)(x))->cl_name)	   \
 	 : (char *)(((PyTypeObject*)(x))->tp_name))
 
 #define PyExceptionInstance_Class(x)					\