In order to support 'bridge' network adapters in parallels
driver we need to plug our veth devices into corresponding
linux bridges.
We are going to do this by reusing our abstraction of
Virtual Networks in terms of PCS. On a domain creation, we
create a new Virtual Network naming it with the same name
as a source bridge for each network  interface.
Having done this, we plug PCS veth interfaces created with names of
target dev into specified bridges using our standard PCS procedures
Signed-off-by: NMaxim Nestratov <mnestratov@parallels.com>
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>