SSL: initialization changes for OpenSSL 1.1.0.

SSL: initialization changes for OpenSSL 1.1.0.

OPENSSL_config() deprecated in OpenSSL 1.1.0.  Additionally,
SSL_library_init(), SSL_load_error_strings() and OpenSSL_add_all_algorithms()
are no longer available if OPENSSL_API_COMPAT is set to 0x10100000L.

The OPENSSL_init_ssl() function is now used instead with appropriate
arguments to trigger the same behaviour.  The configure test changed to
use SSL_CTX_set_options().

Deinitialization now happens automatically in OPENSSL_cleanup() called
via atexit(3), so we no longer call EVP_cleanup() and ENGINE_cleanup()
directly.