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

math/Interpolator.h

@@ -50,7 +50,8 @@ public:
 		// interpolate
 		const int idx1 = (idx2 > 0) ? (idx2 - 1) : (idx2);
 		const float percent = (key - entries[idx1].key) / (float) (entries[idx2].key - entries[idx1].key);
-		return entries[idx1].value + (entries[idx2].value - entries[idx1].value) * percent;
+		const Value res = entries[idx1].value + (entries[idx2].value - entries[idx1].value) * percent;
+		return res;
 
 	}