Merging the py3k-pep3137 branch back into the py3k branch.
No detailed change log; just check out the change log for the py3k-pep3137
branch.  The most obvious changes:

  - str8 renamed to bytes (PyString at the C level);
  - bytes renamed to buffer (PyBytes at the C level);
  - PyString and PyUnicode are no longer compatible.

I.e. we now have an immutable bytes type and a mutable bytes type.

The behavior of PyString was modified quite a bit, to make it more
bytes-like.  Some changes are still on the to-do list.
diff --git a/Lib/test/test_dumbdbm.py b/Lib/test/test_dumbdbm.py
index 3553c19..9a2cb68 100644
--- a/Lib/test/test_dumbdbm.py
+++ b/Lib/test/test_dumbdbm.py
@@ -115,7 +115,7 @@
 
         # Mangle the file by changing the line separator to Windows or Unix
         data = io.open(_fname + '.dir', 'rb').read()
-        if os.linesep == b'\n':
+        if os.linesep == '\n':
             data = data.replace(b'\n', b'\r\n')
         else:
             data = data.replace(b'\r\n', b'\n')