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/pyport.h b/Include/pyport.h
index 5501164..7c684f7 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -135,9 +135,9 @@
  * all platforms (Python interprets the format string itself, and does whatever
  * the platform C requires to convert a size_t/Py_ssize_t argument):
  *
- *     PyBytes_FromFormat
+ *     PyString_FromFormat
  *     PyErr_Format
- *     PyBytes_FromFormatV
+ *     PyString_FromFormatV
  *
  * Lower-level uses require that you interpolate the correct format modifier
  * yourself (e.g., calling printf, fprintf, sprintf, PyOS_snprintf); for