rbutil: Merge rbutil with utils folder.

rbutil uses several components from the utils folder, and can be
considered part of utils too. Having it in a separate folder is an
arbitrary split that doesn't help anymore these days, so merge them.

This also allows other utils to easily use libtools.make without the
need to navigate to a different folder.

Change-Id: I3fc2f4de19e3e776553efb5dea5f779dfec0dc21

utils/rbutilqt/mspack/cabc.c

@@ -0,0 +1,24 @@
+/* This file is part of libmspack.
+ * (C) 2003-2004 Stuart Caie.
+ *
+ * libmspack is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License (LGPL) version 2.1
+ *
+ * For further details, see the file COPYING.LIB distributed with libmspack
+ */
+
+/* CAB compression implementation */
+
+#include "system-mspack.h"
+#include "cab.h"
+
+struct mscab_compressor *
+  mspack_create_cab_compressor(struct mspack_system *sys)
+{
+  /* todo */
+  return NULL;
+}
+
+void mspack_destroy_cab_compressor(struct mscab_compressor *self) {
+  /* todo */
+}