fixed some potential issues with MAC addresses

added corresponding test-cases
switched to newer version of tinyxml due to some issues
adjusted affected code-parts accordingly
for better re-use, moved ceiling-calculation to a new class
some minor fixes
new helper methods
worked on wifi-opt

sensors/radio/setup/WiFiOptimizerStructs.h

@@ -0,0 +1,55 @@
+#ifndef WIFIOPTIMIZERSTRUCTS_H
+#define WIFIOPTIMIZERSTRUCTS_H
+
+#include "../../../geo/Point3.h"
+
+namespace WiFiOptimizer {
+
+	/**
+	 * one entry that is used during optimization:
+	 * combine one RSSI measurement with the position the signal was measured at
+	 */
+	struct RSSIatPosition {
+
+		/** real-world position (in meter) */
+		const Point3 pos_m;
+
+		/** measured signal strength (for one AP) */
+		const float rssi;
+
+		/** ctor */
+		RSSIatPosition(const Point3 pos_m, const float rssi) : pos_m(pos_m), rssi(rssi) {;}
+
+	};
+
+	/**
+	 * for statistics
+	 * after optimiziaton
+	 *
+	 * denotes the difference [error] between one fingerprinted rssi
+	 * at location (x,y,z) and the model estimation for this location
+	 */
+	struct ErrorAtPosition {
+
+		/** real-world position (in meter) */
+		const Point3 pos_m;
+
+		/** measured signal strength (for one AP) */
+		const float scan_rssi;
+
+		/** final model's prediction */
+		const float model_rssi;
+
+		/** ctor */
+		ErrorAtPosition(const Point3 pos_m, const float scan_rssi, const float model_rssi) : pos_m(pos_m), scan_rssi(scan_rssi), model_rssi(model_rssi)  {;}
+
+		/** get the difference [error] between model-estimated-rssi and fingerprinted-rssi */
+		float getError_db() const {
+			return model_rssi - scan_rssi;
+		}
+
+	};
+
+}
+
+#endif // WIFIOPTIMIZERSTRUCTS_H