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
The old tools/mkzenboot has a number of problems: very hard to maintain,
poor integration with rbutil. Restart from scratch by recycling all the
crypto and descrambling code, rewrite the actual firmware modification part
to handle all scenarios in a much clearer way. The code is ready to be
integrated into Rockbox Utility, by using the very similar interface to
mkimxboot.
I copied all the keys from the old mkzenboot, so it can potentially support
the older Creative ports, but since this is untested, I prefer not do so
at the moment. However, I did add a "mixed" boot option to support the
dualboot style used in the older ports.
Change-Id: I80cfc48fa78187baa1b1692e8a30ec7137cea37b
