Now uses the view latest_node_readings so has knowledge of the friendly names

Author: pjb304

feshiedb.py

@@ -371,7 +371,7 @@ def get_acceleromter_readings(self, node):
     def get_latest_node_readings(self):
         if self.db is None:
             raise FeshieDbError()
-        self.db.query("SELECT device, MAX(timestamp) AS timestamp FROM `temperature_readings` WHERE timestamp <= NOW( ) AND device IN ( SELECT id FROM device_info WHERE type = \"Z1\") GROUP BY device ORDER BY timestamp DESC;")
+        self.db.query("SELECT device, name, timestamp FROM latest_node_readings;")
         return self.db.store_result().fetch_row(0)
 
     def get_adc_readings(self, node, adc):