macspoof vdsm hook
=================================
These hooks allow to remove MAC and ARP spoofing filtering
from all of the VM's interfaces or from a specific vNIC.

Installation:
* Use engine-config to set the appropriate custom properties as such:

Custom property for all interfaces in a VM:
    sudo engine-config -s "UserDefinedVMProperties=macspoof=^(true|false)$"

Custom property for a specific vNIC in a VM:
    sudo engine-config -s "CustomDeviceProperties={type=interface;prop={ifacemacspoof=^(true|false)$}}"

* Verify that the custom properties were added properly:
    sudo engine-config -g UserDefinedVMProperties
	sudo engine-config -g CustomDeviceProperties

* Setting UserDefinedVMProperties or CustomDeviceProperties overwrites all
  previous custom properties. If you've already defined other custom properties,
  you may wish to append instead:
    sudo engine-config -g UserDefinedVMProperties
  Copy the value into $PREVIOUS_PROPERTIES, then use:
    sudo engine-config -s "UserDefinedVMProperties=$PREVIOUS_PROPERTIES;macspoof=^(true|false)$"
  Or, for per-device properties:
    sudo engine-config -s "CustomDeviceProperties={type=interface;prop={$PREVIOUS_PROPERTIES;ifacemacspoof=^(true|false)$}}"

Usage:
In the VM configuration window, open the custom properties tab
and add macspoof=true to remove filtering from all interfaces.

In the vNIC profiles configuration window, open the custom properties
tab and add ifacemacspoof=true to remove filtering from the specified interface.

Precedence:
If you set both VM-wide macspoof, and vNIC specific ifacemacspoof, then the
VM wide setting takes precedence. For example, if a VM's macspoof is True
(Disable the filter), but a vNIC's ifacemacspoof is False (Enable the filter)
then the filter for all vNICs on that VM will be disabled.
