* DBUS-API: Document new "LastApprovalRequest" client property.
* mandos (Client.last_approval_request): New attribute. (Client.need_approval): New method. (ClientDBus.need_approval): - '' - (ClientDBus.NeedApproval): Call self.need_approval(). (ClientDBus.LastApprovalRequest_dbus_property): New D-Bus property.
* mandos-monitor: Show timeout counter during approval delay. (MandosClientWidget._update_timer_callback_lock): New. (MandosClientWidget.property_changed): Override to also call using_timer if ApprovalPending property is changed. (MandosClientWidget.using_timer): New method. (MandosClientWidget.checker_completed): Use "using_timer". (MandosClientWidget.need_approval): - '' - (MandosClientWidget.update): Show approval delay timer.