added interface for walkers

some new helper methods
added interpolater for paths

grid/walk/GridWalk.h

@@ -0,0 +1,15 @@
+#ifndef GRIDWALK_H
+#define GRIDWALK_H
+
+#include "GridWalkState.h"
+#include "../Grid.h"
+
+template <typename T> class GridWalk {
+
+public:
+
+	virtual GridWalkState<T> getDestination(Grid<T>& grid, const GridWalkState<T> start, const float distance_m) = 0;
+
+};
+
+#endif // GRIDWALK_H