More work on SSL support.

More work on SSL support.

* Much expanded test suite:

  All protocols tested against all other protocols.
  All protocols tested with all certificate options.
  Tests for bad key and bad cert.
  Test of STARTTLS functionality.
  Test of RAND_* functions.

* Fixes for threading/malloc bug.

* Issue 1065 fixed:

  sslsocket class renamed to SSLSocket.
  sslerror class renamed to SSLError.
  Function "wrap_socket" now used to wrap an existing socket.

* Issue 1583946 finally fixed:

  Support for subjectAltName added.
  Subject name now returned as proper DN list of RDNs.

* SSLError exported from socket as "sslerror".

* RAND_* functions properly exported from ssl.py.

* Documentation improved:

  Example of how to create a self-signed certificate.
  Better indexing.