create-dc: Update to use new provisioning process

Instead of running `virt-install` directly from the `create-dc.sh`
script, it now relies on `newvm.sh`.  This will ensure that VMs created
to be domain controllers will conform to the same expectations as all
other machines, such as using the libvirt domain metadata to build
dynamic inventory.

Similarly, the `create-dc.yml` playbook now imports the `host-setup.yml`
playbook, which covers the basic setup of a new machine.  Again, this
ensures that the same policy is applied to DCs as to other machines.

Finally, domain controller machines now no longer use _winbind_ for
OS user accounts and authentication.  This never worked particularly
well on DCs anyway (particularly because of the way _winbind_ insists on
using domain-prefixed user accounts when it runs on a DC), and is now
worse with recent Fedora changes.  Instead, DCs now have local users who
authenticate via SSH certificates, the same as other current-generaton
servers.

group_vars/pyrocufflink-ad.yml

@@ -0,0 +1 @@
+krb5_realm: PYROCUFFLINK.BLUE

group_vars/pyrocufflink/main.yml

@@ -1,6 +1,5 @@
 ansible_become_method: sudo
 
-krb5_realm: PYROCUFFLINK.BLUE
 samba_security: ads
 samba_use_winbind: true
 pam_winbind: true