Add Error state

Reusing an SSL object when it has encountered a fatal error can
have bad consequences. This is a bug in application code not libssl
but libssl should be more forgiving and not crash.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(cherry picked from commit a89db885)

Conflicts:
	ssl/s3_srvr.c
	ssl/ssl_stat.c