some fixes [multithreading,..]

needed interface changes [new options]
logger for android
wifi-ap-optimization
new test-cases

nav/dijkstra/DijkstraPath.h

@@ -20,6 +20,11 @@ private:
 
 public:
 
+	/** empty ctor */
+	DijkstraPath() {
+		;
+	}
+
 	/** ctor from end- to start-node */
 	DijkstraPath(const DijkstraNode<T>* end, const DijkstraNode<T>* start) {