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/Doc/includes/run-func.c b/Doc/includes/run-func.c
index 1b7c942..5a7df0d 100644
--- a/Doc/includes/run-func.c
+++ b/Doc/includes/run-func.c
@@ -13,7 +13,7 @@
     }
 
     Py_Initialize();
-    pName = PyBytes_FromString(argv[1]);
+    pName = PyString_FromString(argv[1]);
     /* Error checking of pName left out */
 
     pModule = PyImport_Import(pName);