Defines for the different command classes as defined in the MMC and SD
specifications.

Removes the check for high command classes and instead checks that the
command classes needed are present.
Previous solution killed forward compatibility at no apparent gain.

Signed-of-by: Pierre Ossman

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!