tests: setupNetworks add one or more vlans.

Added a couple of functional tests:

* testSetupNetworksAddVlan
* testSetupNetworksAddManyVlans

covering the behaviour of setupNetworks when adding
one or more vlans.

Change-Id: I62fa6de1faa7d4e886c45361a001b0009fd92502
Signed-off-by: Giuseppe Vallarelli <gvallare@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/17432
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>