Add 3.15.6 example app (for compilation tests)

exampleApp/src/exampleMain.cpp

@@ -0,0 +1,23 @@
+/* exampleMain.cpp */
+/* Author:  Marty Kraimer Date:    17MAR2000 */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "epicsExit.h"
+#include "epicsThread.h"
+#include "iocsh.h"
+
+int main(int argc,char *argv[])
+{
+    if(argc>=2) {    
+        iocsh(argv[1]);
+        epicsThreadSleep(.2);
+    }
+    iocsh(NULL);
+    epicsExit(0);
+    return(0);
+}