Add SSL_CONF support to ssltest.
Add SSL_CONF support to ssltest.

Add command line support for SSL_CONF: server side arguments are
prefixed by -s_ (e.g. -s_no_ssl3) and client side with -c_.
Reviewed-by: Matt Caswell <1fa2ef4755a9226cb9a0a4840bd89b158ac71391@openssl.org>

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl