The *libvirt-daemon-driver-network* package provides support for
managing virtual networks with libvirt. It is necessary in order to use
managed networks in VM configuration, as opposed to directly specifying
VM network interfaces in their domain configuration.
This commit adds a systemd unit to enable the Kernel Same-page Merging
daemon on VM hosts. This allows much greater virtual machine density,
especially when many VMs are running the same guest OS.
