sp: _refreshDomainLinks must not change the metadata

Method _refreshDomainLinks is used on HSM hosts and it shouldn't change
the pool metadata. In order to make sure that the domains are properly
marked as regular we fix their role during startSpm and activateSD.

In this patch:
- add _updateDomainsRole to make sure that all the regular domains are
  marked as regular (used at startSpm time)
- mark domain as regular during activation

Change-Id: I2ecf801d58b34c1c811e311e3779887a406af5f0
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/22131
Reviewed-by: Dan Kenigsberg <danken@redhat.com>