Fix the no-tls1 option

This also fixes no-tls which is an alias for no-tls1 in 1.0.2 (it is not
possible to do no-tls1_1 or no-tls1_2 in 1.0.2).

Because it is not possible to disable TLS1.1 or TLS1.2 it no longer follows
that disabling TLS1.0 should force the disabling of tlsext.

Also a few missing ifdef guards.

GitHub Iusse#935

Reviewed-by: Rich Salz <rsalz@openssl.org>