[mkroot] The repo is back on github.

[Rob Landley]

Thanks to Carl Dong.

The most recent status update is on

  https://www.patreon.com/posts/job-change-and-18518050

I caught up on the kernel issues, although it looks like 4.18 is probably the
next one that (might) build without any patches because the perl removal is
sitting in the arm maintainer's "fixes" branch and not getting submitted
upstream for 4.17. (Blah.)

I still want to merge mkroot into toybox, but half the existing infrastructure
goes away when I do that, so I guess this is of historical interest. And
removing the two remaining busybox commands (hush and route) is taking a while.

The idea for the new design is basically: 1) Eliminate busybox, 2) glue
module/kernel to the end of mkroot.sh, 3) Remove the download plumbing, 4) merge
it into toybox.

If the build is part of toybox we don't need to download toybox. If busybox is
gone we don't need to download busybox. That just leaves linux, and there's no
point having download infrastructure for just one package. I can have a LINUX=
environment variable point to the kernel source, and if that variable isn't set,
it'll skip the kernel build and cpio packaging.

That means the download, extract, and cleanup infrastructure can all go: for the
kernel build do the "cp -s" snapshot and then do a "make distclean" in it before
configure and make.

At that point, half the command line option parsing is unnecessary, no need for
"-d", no modules... but maybe I should preserve them in the old repo for posterity?

Anyway: toybox needs route and a shell capable of running the init script. Those
are the next big todo items here, then the last remnants of busybox can go away.

Rob