Unit Tests

- All unit tests most now clean up a residual undo.data file, so the
  number of tests increased, but with no benefit.

src/main.h

@@ -24,6 +24,8 @@
 //     USA
 //
 ////////////////////////////////////////////////////////////////////////////////
+#ifndef INCLUDED_MAIN
+#define INCLUDED_MAIN
 
 #define FEATURE_TDB_OPT 1   // TDB Optimization reduces file I/O.
 #define FEATURE_NEW_ID  1   // Echoes back new id.
@@ -154,4 +156,5 @@ template <class T> void listDiff (
   }
 }
 
+#endif
 ////////////////////////////////////////////////////////////////////////////////