Breaking ground for PEP 3137 implementation:

Get rid of buffer().  Use memoryview() in its place where possible.
In a few places, do things a bit different, because memoryview()
can't slice (yet).
diff --git a/Lib/_abcoll.py b/Lib/_abcoll.py
index 5fbb219..2a9676f 100644
--- a/Lib/_abcoll.py
+++ b/Lib/_abcoll.py
@@ -491,7 +491,7 @@
 
 Sequence.register(tuple)
 Sequence.register(basestring)
-Sequence.register(buffer)
+Sequence.register(memoryview)
 
 
 class MutableSequence(Sequence):