some fixes [multithreading,..]

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

grid/factory/v2/Stairs2.h

@@ -112,7 +112,7 @@ public:
 			const Point3 p4 = quad.p4 * 100;
 
 			// get the z-value from one of the both triangles
-			int z_cm;
+//			int z_cm;
 			float u,v,w;
 			if (helper.bary(p, p1.xy(), p2.xy(), p3.xy(), u, v, w)) {
 				sn.z_cm = p1.z*u + p2.z*v + p3.z*w;
@@ -124,7 +124,7 @@ public:
 		}
 
 		// this might lead to stairs the start slightly above the starting-floor
-		// or end slightly below the ending floor. this would lead to DISCONNECTION!
+		// or ending slightly below the ending floor. this would lead to DISCONNECTION!
 		// therefore re-scale the z-values to ensure they start at floor1 and end at floor 2
 		float minZ = +9999999;
 		float maxZ = -9999999;