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/Mac/Modules/MacOS.c b/Mac/Modules/MacOS.c
index 9148fe0..07a3434 100644
--- a/Mac/Modules/MacOS.c
+++ b/Mac/Modules/MacOS.c
@@ -706,7 +706,7 @@
 	** some of the image and sound processing interfaces on the mac:-(
 	*/
 	{
-		PyBytesObject *p = 0;
+		PyStringObject *p = 0;
 		long off = (long)&(p->ob_sval[0]);
 		
 		if( PyDict_SetItemString(d, "string_id_to_buffer", Py_BuildValue("i", off)) != 0)