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/Modules/cjkcodecs/cjkcodecs.h b/Modules/cjkcodecs/cjkcodecs.h
index c06319e..4005bcf 100644
--- a/Modules/cjkcodecs/cjkcodecs.h
+++ b/Modules/cjkcodecs/cjkcodecs.h
@@ -261,7 +261,7 @@
 	const MultibyteCodec *codec;
 	const char *enc;
 
-	if (!PyBytes_Check(encoding)) {
+	if (!PyString_Check(encoding)) {
 		PyErr_SetString(PyExc_TypeError,
 				"encoding name must be a string.");
 		return NULL;
@@ -271,7 +271,7 @@
 	if (cofunc == NULL)
 		return NULL;
 
-	enc = PyBytes_AS_STRING(encoding);
+	enc = PyString_AS_STRING(encoding);
 	for (codec = codec_list; codec->encoding[0]; codec++)
 		if (strcmp(codec->encoding, enc) == 0)
 			break;