The *named* role now supports generating configuration for authoritative
DNS zones and DNSSEC keys. Zones are defined by populating the
`named_zones` variable with a list of objects describing the zone. Zone
properties can include:
* `name`: The DNS domain name
* `type`: The zone type, defaults to `master`
* `allow_update`: A list of hosts/networks or DNSSEC key names (which
must be specified as an object with a `key` property)
* `update_policy`: A list of BIND update policy statements
* `ttl`: The default (minimum) TTL for the zone
* `origin`: The authoritative name server for the zone
* `refresh`, `retry`, `expire`: Record cache timeout values
* `default_records`: A list of default records, defined as objects with
the following properties:
* `name`: The RR name
* `type`: The RR type (default: `A`)
* `value`: The RR value
Zone files will be created in `/var/named/dynamic`. Existing zone files
will **not** be overwritten; management of zone records is done using
`nsupdate` or similar.