Update libvirt related tags when libvirt connection state changes.

    def virt_connected(self, value):

        self._virt_connected = value

        # update tags

        for tag in ('vir_status', 'hvver', 'libvirtver'):

        for tag in ('vir_status', 'sto', 'nvm', 'vmpaused', 'vmstarted',

                    'vmstopped', 'hvver', 'libvirtver', 'hv'):

            # TODO tag annoucement

            self.tag_db['__main__'][tag].calculate_value()

    def start(self):

                             state)

                vm.state = state

        # update domain state counts

        for tag in ('nvm', 'vmpaused', 'vmstarted', 'vmstopped'):

            # TODO tag announcement

            self.handler.tag_db['__main__'][tag].calculate_value()

    def vm_define(self, xml_desc):

        """Create a VM on the Hypervisor

        :param str xml_desc: XML description in libvirt format

    @state.setter

    def state(self, value):

        self._state = value

        # TODO tag announcement

        self.tags['status'].value = value

    @property