Rename PyUnicode_AsString -> _PyUnicode_AsString and
PyUnicode_AsStringAndSize -> _PyUnicode_AsStringAndSize to mark
them for interpreter internal use only.

We'll have to rework these APIs or create new ones for the
purpose of accessing the UTF-8 representation of Unicode objects
for 3.1.
diff --git a/Modules/syslogmodule.c b/Modules/syslogmodule.c
index 6c78679..c6a3b36 100644
--- a/Modules/syslogmodule.c
+++ b/Modules/syslogmodule.c
@@ -72,7 +72,7 @@
 	S_ident_o = new_S_ident_o;
 	Py_INCREF(S_ident_o);
 
-	ident = PyUnicode_AsString(S_ident_o);
+	ident = _PyUnicode_AsString(S_ident_o);
 	if (ident == NULL)
 		return NULL;
 	openlog(ident, logopt, facility);
@@ -97,7 +97,7 @@
 			return NULL;
 	}
 
-	message = PyUnicode_AsString(message_object);
+	message = _PyUnicode_AsString(message_object);
 	if (message == NULL)
 		return NULL;
 	Py_BEGIN_ALLOW_THREADS;