some fixes [multithreading,..]

needed interface changes [new options]
logger for android
wifi-ap-optimization
new test-cases

sensors/radio/model/WiFiModel.h

@@ -16,6 +16,9 @@ public:
 //	/** get the given access-point's RSSI at the provided location */
 //	virtual float getRSSI(const LocatedAccessPoint& ap, const Point3 p) = 0;
 
+	/** get a list of all APs known to the model */
+	virtual std::vector<AccessPoint> getAllAPs() const = 0;
+
 	/**
 	 * get the RSSI expected at the given location (in meter)
 	 * for an AP identified by the given MAC.