ADD: new track message, Entity class and Position class

libs/geographiclib/wrapper/c/geoidtest.c

@@ -0,0 +1,13 @@
+#include <stdio.h>
+#include "cgeoid.h"
+
+#if defined(_MSC_VER)
+/* Squelch warnings about scanf */
+#  pragma warning (disable: 4996)
+#endif
+
+int main() {
+  double lat, lon, h;
+  while(scanf("%lf %lf %lf", &lat, &lon, &h) == 3)
+    printf("%.3f\n", HeightAboveEllipsoid(lat, lon, h));
+}