[libvirt] [PATCHv2 0/2] qemu: support live update of an interface's filter

These two patches enable making a live change to the nwfilter of a guest's interface via virDomainUpdateDeviceFlags (virsh update-device). Differences from V1: 1) add patch from Stefan Berger to do a proper comparison of the values stored in the filterparams hashtable. 2) simplify virNWFilterHashTableEqual to use Stefan's new function, and remove a couple of pointless comparisons based on Stefan's review.