Use faster PyUnicode_FromEncodedObject() for bytes/bytearray.decode().
Add new PyCodec_KnownEncoding() API.
Add new PyUnicode_AsDecodedUnicode() and PyUnicode_AsEncodedUnicode() APIs.
Add missing PyUnicode_AsDecodedObject() to unicodeobject.h
Fix punicode codec to also work on memoryviews.
(branch-creation time) up to 43067. 43068 and 43069 contain a little
swapping action between re.py and sre.py, and this mightily confuses svn
merge, so later changes are going in separately.
This merge should break no additional tests.
The last-merged revision is going in a 'last_merge' property on '.' (the
branch directory.) Arbitrarily chosen, really; if there's a BCP for this, I
couldn't find it, but we can easily change it afterwards ;)