Add device availability functionality for HASS based on router devices ping and attribute reporting also available on battery-powered devices (#761)

* Discovery on HASS restart and last_message attribute added

- On restarting Home Assistant, resending device discovery information
- Add timestamp on receiving message from Zigbee

* Add option: add_timestamp in settings

* typo

* Update homeassistant.js

* Update homeassistant.js

* Update homeassistant.js

* Update controller.js

* Update zigbee.js

* Add files via upload

* Update zigbee.js

* Update deviceAvailabilityHandler.js

* Update deviceAvailabilityHandler.js

* Update deviceAvailabilityHandler.js

* Update deviceAvailabilityHandler.js

* Update deviceAvailabilityHandler.js

* Update deviceAvailabilityHandler.js

* Update deviceAvailabilityHandler.js

* Update homeassistant.js

* Update deviceAvailabilityHandler.js

* Update deviceAvailabilityHandler.js

* Update homeassistant.js

* Fix checkonline callback.

* Refactor.

* Refactor.

lib/zigbee.js

@@ -159,18 +159,18 @@ class Zigbee {
         }
     }
 
-    ping(deviceID) {
+    ping(deviceID, callback) {
         let friendlyName = 'unknown';
         const device = this.shepherd._findDevByAddr(deviceID);
         const ieeeAddr = device.ieeeAddr;
+
         if (settings.getDevice(ieeeAddr)) {
             friendlyName = settings.getDevice(ieeeAddr).friendly_name;
         }
 
         if (device) {
-            // Note: checkOnline has the callback argument but does not call callback
             logger.debug(`Check online ${friendlyName} ${deviceID}`);
-            this.shepherd.controller.checkOnline(device);
+            this.shepherd.controller.checkOnline(device, callback);
         }
     }