many changes and updates

- changed the wifi-estimation api
- adjusted test-cases
- worked on grid-bulding and grid-importance
- new walking modules
- fixed some minor issues

sensors/radio/model/WiFiModel.h

@@ -4,14 +4,25 @@
 #include "../LocatedAccessPoint.h"
 
 /**
- * interface for signal-strength prediction models
+ * interface for signal-strength prediction models.
+ *
+ * the model is passed a MAC-address of an AP in question, and a position.
+ * hereafter the model returns the RSSI for this AP at the questioned location.
  */
 class WiFiModel {
 
 public:
 
-	/** get the given access-point's RSSI at the provided location */
-	virtual float getRSSI(const LocatedAccessPoint& ap, const Point3 p) = 0;
+//	/** get the given access-point's RSSI at the provided location */
+//	virtual float getRSSI(const LocatedAccessPoint& ap, const Point3 p) = 0;
+
+	/**
+	 * get the RSSI expected at the given location (in meter)
+	 * for an AP identified by the given MAC.
+	 *
+	 * if the model can not predict the RSSI for an AP, it returns NaN!
+	 */
+	virtual float getRSSI(const MACAddress& accessPoint, const Point3 position_m) const = 0;
 
 };