tests: addNetwork bond with one or many vlans.

Added a couple of functional tests:

* testAddNetworkBondWithManyVlans
* testAddNetworkVlanBond

covering the behaviour related to addNetwork using bond
and vlans.

Change-Id: I84b1582bbc9de09009a7e076386658035317f7db
Signed-off-by: Giuseppe Vallarelli <gvallare@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/17387
Reviewed-by: Antoni Segura Puimedon <asegurap@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>