Set KVM's guest name

Match the beginning of libvirt's kvm invocation, and help with VM identification.

scripts.go

@@ -81,6 +81,7 @@ func runVM(vm *VM, network *Network) RunnableTask {
 
 	return newCmd(
 		"/usr/bin/qemu-system-x86_64",
+		"-name", "guest="+vm.Hostname+",debug-threads=on",
 		"-no-user-config",
 		"-nodefaults",
 		"-no-reboot",