Refactor marshall utilities out, some clean-up, and prepare iOS/macOS project for libjson-c

core/c/mpw-util.h

@@ -16,12 +16,13 @@
 // LICENSE file.  Alternatively, see <http://www.gnu.org/licenses/>.
 //==============================================================================
 
-#include <stdio.h>
-#include "mpw-types.h"
-
 #ifndef _MPW_UTIL_H
 #define _MPW_UTIL_H
 
+#include <stdio.h>
+
+#include "mpw-types.h"
+
 //// Logging.
 
 #ifndef trc