huge commit

- worked on about everything
- grid walker using plugable modules
- wifi models
- new distributions
- worked on geometric data-structures
- added typesafe timestamps
- worked on grid-building
- added sensor-classes
- added sensor analysis (step-detection, turn-detection)
- offline data reader
- many test-cases

sensors/radio/WiFiMeasurements.h

@@ -0,0 +1,18 @@
+#ifndef WIFIMEASUREMENTS_H
+#define WIFIMEASUREMENTS_H
+
+#include <vector>
+
+#include "WiFiMeasurement.h"
+
+/**
+ * group of several wifi measurements
+ */
+struct WiFiMeasurements {
+
+	/** all contained measurements */
+	std::vector<WiFiMeasurement> entries;
+
+};
+
+#endif // WIFIMEASUREMENTS_H