added helper methods for debug printing

fixed issue when reading wifi entries within old walk files
worked on earth-registration
added corresponding test-cases
other minor changes

sensors/offline/Sensors.h

@@ -9,12 +9,12 @@ namespace Offline {
 		LIN_ACC = 2,
 		GYRO = 3,
 		BARO = 5,
+		COMPASS = 6,		// also called "orientatioN"
 		WIFI = 8,
 		BEACON = 9,
-		COMPASS = 15,
 		GPS = 16,
 		GROUND_TRUTH = 99,
-		POS = 1001,		// IPIN2016
+		POS = 1001,			// IPIN2016
 	};
 
 	template <typename T> struct TS {