app dir changed and src dir removed

bs/cmds/exit.c

@@ -0,0 +1,11 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "exit.h"
+
+const char cmd_exit_help[] = "Bla bla.";
+
+int cmd_exit(jtag_core *jc, int argc, char **argv) {
+    jtagcore_deinit(jc);
+    exit(0);
+}