[libvirt] [PATCH 0/2] network: virNetworkUpdate section backends

These patches are the backends for ip-dhcp-range and portgroups. Since virsh, the bridge driver, and the toplevel of the NetworkObj function of virNetworkUpdate already support all sections, only the lowest level routine in network_conf.c needs to be modified (an "unsupported" error log is replaced with real functionality). These functions are self-contained (each updates the contents of a single static function) and only used by the new virNetworkUpdate API; no other code is touched by the patches, so they are fairly safe to add.