engine: Edit Network and apply to hosts at once

Editing a network and applying its changes to all
of the eligible hosts via a single action is enabled by
sync-ing the network on the hosts (if the network wasn't
renamed)

See: http://www.ovirt.org/Features/MultiHostNetworkConfiguration

Bug-Url: http://bugzilla.redhat.com/1040580
Change-Id: Iec04c7fb0c29ba6f61b7d788a9c3917f5d46554e
Signed-off-by: Moti Asayag <masayag@redhat.com>