SSL changes:

*) Added support for TLSv1.1, TLSv1.2 in ssl_protocols directive.

   Support for TLSv1.1 and TLSv1.2 protocols was introduced in
   OpenSSL 1.0.1 (-beta1 was recently released).  This change makes it
   possible to disable these protocols and/or enable them without other
   protocols.

*) Removed ENGINE_load_builtin_engines() call.

   It's already called by OPENSSL_config().  Calling it again causes
   some openssl engines (notably GOST) to corrupt memory, as they don't
   expect to be created more than once.

Minor cleanup:

*) Changed error message to be more appropriate in the imaginary
   "open_file_cache max=0" case.

*) Fixed NGX_CONF_TAKE1/NGX_CONF_FLAG misuse.

Fixed range checking for the "somaxconn" sysctl.  Fixed port range checking.

A new fix for the case when ssl_session_cache defined, but ssl is not
enabled in any server. The previous r1033 does not help when unused zone
becomes used after reconfiguration, so it is backed out.

The initial thought was to make SSL modules independed from SSL implementation
and to keep OpenSSL code dependance as much as in separate files.

SSL related fixes:

*) MSIE export versions are rare now, so RSA 512 key is generated on demand
   and is shared among all hosts instead of pregenerating for every HTTPS host
   on configuraiton phase. This decreases start time for configuration with
   large number of HTTPS hosts.
*) ECDHE support; patch by Adrian Kotelba
*) fix build by gcc46 with -Wunused-value option
*) fix SSL connection issues on platforms with 32-bit off_t
*) do not try to reuse and save a SSL session for a peer created on the fly
   by ngx_http_upstream_create_round_robin_peer(), since the peer lives
   only during request so the saved SSL session will never be used again
   and just causes memory leak

patch by Rob Stradling