We already have a dynamic system for managing static group management.
Use it for the disabled group so that the rules for managing the members
are not different.
Also, update the disabled list to match reality.
Also, Update docs because hosts are no longer groups
The upstream OpenStack Inventory in Ansible was fixed to no longer
return each cloud host as its own group unless there are duplicates for
the host in question. This means it's no longer the right thing to do
to put hosts into disabled:children - disabled is just fine.
Change-Id: I95c83ed64801db15ad99a14547895f3520356f99
765c1474b7