This patch implements the core driver and provides - management functionality for managing the filter XMLs - compiling the internal filter representation into ebtables rules - applying ebtables rules on a network (tap,macvtap) interface - tearing down ebtables rules that were applied on behalf of an interface - updating of filters while VMs are running and causing the firewalls to be rebuilt - other bits and pieces Signed-off-by: Stefan Berger <stefanb@us.ibm.com>