Also update the test_ssl.py to cpython rev 2c9ff9e (head). This fixes the
problems with invalid certs for svn.python.org.

These tests include much more testing of the new-in-2.7.9 SSLContext
settings, which revealed some problems in our hostname validation, our
handling of read/write/do_handshake for closed sockets, and the missing
alpn_selected method.