I updated sslproto3.patch with my remarks: sslproto-4.patch

Main differences with sslproto3.patch (unsorted):

* write_eof raises NotImplementedError
* fix write_buffer_size: use data, not offset
* use tuples in the write backlog
* data_received exits the loop when it gets an empty string (ignore following data, but an empty string must be at the end of the list according to Antoine)
* SSLPipe._write_backlog is now a deque (should be more efficient since we remove the head of the list in _process_write_backlog)
* always store and pass the server hostname, even if SNI is not supported
* deny calling shutdown() twice
* Remove ConnectionAbortedError special case: I would like to reproduce to understand it, and document it
* Set the default read parameter to 256 KB instead of 64 KB: reuse constant from selector_events.py
* SSLPipe: use a different attribute to store the shutdown callback

Remarks:

* sslproto looks to be based on gruvi/ssl.py of the gruvi project written by Geert
Jansen. We should mention the author in the commit.
* _process_write_backlog(): I don't understand why offset is set to 1 for handshake and shutdown