Vancouver is now able to use the Intel 82576 device model from NUL to
give VMs access to the network via the nic_bridge service. In order to
integrate the device model, it had to be renamed to i82576 due to XML
limitations. This is done by a patch applied via the 'make prepare'
mechanism.
Although current network card models in Vancouver panic if they can't
get a MAC address, the OP_GET_MAC hostop now fails gracefully in the
case where no nic_drv or nic_bridge is available.
