fixed some compiler warnings

added equality checks to sensor-data classes
more robust sensor reader [fixed some issues]
added support for gps
added support for compass
added sensor-data-writer
added test-cases
minor changes

sensors/offline/Sensors.h

@@ -0,0 +1,38 @@
+#ifndef OFFLINE_SENSORS_H
+#define OFFLINE_SENSORS_H
+
+namespace Offline {
+
+	enum class Sensor {
+		ACC = 0,
+		GRAVITY = 1,
+		LIN_ACC = 2,
+		GYRO = 3,
+		BARO = 5,
+		WIFI = 8,
+		BEACON = 9,
+		COMPASS = 15,
+		GPS = 16,
+		GROUND_TRUTH = 99,
+		POS = 1001,		// IPIN2016
+	};
+
+	template <typename T> struct TS {
+		const uint64_t ts;
+		T data;
+		TS(const uint64_t ts) : ts(ts) {;}
+		TS(const uint64_t ts, const T& data) : ts(ts), data(data) {;}
+	};
+
+	/** entry for one sensor */
+	struct Entry {
+		Sensor type;
+		uint64_t ts;
+		int idx;
+		Entry(Sensor type, uint64_t ts, int idx) : type(type), ts(ts), idx(idx) {;}
+	};
+
+
+}
+
+#endif // OFFLINE_SENSORS_H