Added configuration options and templating for smtps options
'smtpd_sasl_auth_enable' and 'smtpd_client_restrictions'. Neither is
certain and fixed. You might want to restrict authenticated sessions to
the submission port for example, and you might or might not want to
accept mail from unauthenticated connections on 465.

Note that the use of port 465 isn't standards compliant anyway but I
feel like to unauthenticated clients it should behave like port 25.

Hmm... Greylisting on 465...
Added default content filter for smtps. Can be overriden but defaults to
the same as smtp.
Added configuration options/templating for the full suit of postfix
restriction lists:

    smtpd_client_restrictions
    smtpd_helo_restrictions
    smtpd_sender_restrictions
    smtpd_recipient_restrictions
    smtpd_data_restrictions
    smtpd_end_of_data_restrictions
Added support for 'smtpd_helo_required'.