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

nav/dijkstra/Dijkstra.h

@@ -1,10 +1,12 @@
 #ifndef DIJKSTRA_H
 #define DIJKSTRA_H
 
-
+#include <cmath>
 #include <vector>
 #include <algorithm>
 #include <unordered_set>
+#include <unordered_map>
+
 #include <list>
 #include <set>