Removed from milestone 2.7.3 because #185 is expected to resolve (within a somewhat broader in scope).

@gbach : I've merged similar code as part of #185, so we can close this. Thanks however for your interest in solving it and keeping this on the to-do list, which has led to tidying up several loose ends in this bit of _socket.py.

The use of a memoryview is good, and it seemed to improve performance, used consistently, in send() too.

You have to remember to dispose of them because they lock the underlying object. Even a slice of a memoryview is a memoryview, which I forgot in my first change set. with is a good idiom for this.