worked on grid-walking

worked on grid-generation
added helper library for nav-meshes
started working on nav meshes

grid/walk/v3/Walker.h

@@ -184,7 +184,9 @@ namespace GW3 {
 
 			}
 
+#if (GRID_MODE == GM_BOX)
 			Assert::isTrue(grid.hasNodeFor(grid.toGridPoint(res.position)), "end-point not found on grid");
+#endif
 
 			return res;