* For non-ASCII domain names, we will keep the Unicode encoding in our users/aliases table. This is nice for the user and also simplifies things like sorting domain names (using Unicode lexicographic order is good, using ASCII lexicogrpahic order on IDNA is confusing).
* Write nsd config, nsd zone files, nginx config, and SSL CSRs with domains in IDNA-encoded ASCII.
* When checking SSL certificates, treat the CN and SANs as IDNA.
* Since Chrome has an interesting feature of converting Unicode to IDNA in <input type="email"> form fields, we'll also forcibly convert IDNA to Unicode in the domain part of email addresses before saving email addresses in the users/aliases tables so that the table is normalized to Unicode.
* Don't allow non-ASCII characters in user account email addresses. Dovecot gets confused when querying the Sqlite database (which we observed even for non-word ASCII characters too, so it may not be related to the character encoding).
If bind9 isn't running, dont proceed with other checks because we can't do DNS checks. Even though we skip, add error handling so that a failed call to rndc doesn't crash and that a timeout in a DNS check doesn't crash the status checks.
Relative hostnames have a fall-back lookup with the machine's hostname appended, which makes no sense. Add a period, e.g. "my.hostname.com" => "my.hostname.com.", to prevent that.
This caused false positive Spamhaus checks. Fixes#185.
* If the PRIMARY_HOSTNAME is in a zone with a DS record set at the registrar, show any DNSSEC failure (but only a failure) immediately since it is probably the cause of other DNS errors displayed later.
* For zones, if a DS record is set at the register, do the DNSSEC test first because even the NS test will fail if DNSSEC is improperly configure.
* But if a DS record is not set, the this is just a suggestion to configure DNSSEC so offer the suggestion last --- after mail and web checks.
see https://discourse.mailinabox.email/t/dns-nameserver-gandi-glue-records-issues/105/3
