[Cryptech Core] git, again

[Rob Austein]

I don't know enough (yet) about what the tool chain project is going
to entail to have an informed opinion on what the tree for that will
look like.  Partly because of this, I suspect we'll want multiple
repositories.  How many, I do not know.

Proposed rule of thumb (a bit difficult to apply in the case of some
of this stuff, but try it on for size at conceptual level): if, in
something like the Debian software universe, a collection of stuff is
sufficiently interrelated that one would use a single debian/control
file to build one or more binary packages, it should be a single
repository; if it would be multiple independent debian/control files,
it's multiple projects, thus multiple repositories.  I realize that
this does not map perfectly to the hardware-building universe, but I
suspect the general ideas is clear.

RFC 1925 (5) may be relevant here :)