Added filepath to heightmap class

src/contour_creator.hh

@@ -15,6 +15,7 @@ class HeightMap
         int height; //!< height of image in pixels
         float min; //!< Minimum value in image
         float max; //!< Maximum value in image
+        const char* filepath; //!< Where the heightmap was read from
         OGRSpatialReference reference_system;
         HeightMap(const char* filepath);
         ~HeightMap()
@@ -22,7 +23,6 @@ class HeightMap
             delete[] data;
             delete[] geotransform;
         }
-        const char* filepath; //!< Where the heightmap was read from
         float get_pixel(int x,int y);
         void blur(float standard_deviation);
         void statistics(); //!< Print statistical information about the heightmap