Updates to VIF port's security_groups field not reflected in underlying IPAddrGroups

Translation of VIF port updates does not take into account the possibility that the port's security_groups field may have changed. Consequently, adding a security group ID to a VIF port's security_groups does not add the VIF port's IP address(es) to the corresponding Midonet IPAddrGroup. Likewise, removing the security group ID from the port's security_groups does not remove the port's IP address(es) from the underlying IPAddrGroup.

The updated port will begin using the security rules for any added security groups and stop using the security rules for any dremoved security groups, as it should. However, other ports with security-group-based rules (e.g., accept all TCP traffic on port 10000 from members of security group "sg1") will continue to function as though the port had not been added/removed to the security group (e.g., continue to accept traffic from the port even after it has been removed from group "sg1").