This PR adds support for TLSv1.3 to run_server_preference(). It only provides partial support, as it only works if the support supports and earlier TLS protocol (in order to determine whether the server has a cipher order). It also will only show TLSv1.3 as the "Negotiated protocol" if $OPENSSL supports TLSv1.3.
This PR also fixes a bug in which the variable "proto" was defined as used as both a regular variable and as an array.
Update `$TLS12_CIPHER` to contain only 128 ciphers (so that it will work with servers that can't handle larger ClientHello messages), and also add some newer ciphers to `$TLS12_CIPHER`. Also define a `$TLS12_CIPHER_2ND_TRY` containing a list of 127 ciphers that do not appear in `$TLS12_CIPHER`. `$TLS12_CIPHER_2ND_TRY` is used in `run_protocols()` in order to perform a second test against servers that do not establish a TLSv1.2 connection when offered `$TLS12_CIPHER`.
