Add an extra mkfs blocker.
Let the sync type be configurable.

Useful for setups where getting nfs sync working is a PITA.
Support adding multiple additional disks to gluster machines.

You can easily configure this by settings the disks integer in the
puppet-gluster.yaml file or with the --gluster-disks= parameter.

If this is set to the default of zero (0) then no disks are added.