changes from the laptop

- some should be the same as previous commit (sorry!)
- some should be new: LINT checks, ...?

sensors/radio/WiFiMeasurements.h

@@ -23,8 +23,8 @@ struct WiFiMeasurements {
 	}
 
 	/** get the measurements for the given MAC [if available] otherwise null */
-	WiFiMeasurement* getForMac(const MACAddress& mac) {
-		for (WiFiMeasurement& m : entries) {
+	const WiFiMeasurement* getForMac(const MACAddress& mac) const {
+		for (const WiFiMeasurement& m : entries) {
 			if (m.getAP().getMAC() == mac) {
 				return &m;
 			}