With this tool, we can send content to a TRS-80 directly to floppy.
This paves the way to writing ourselves a set of disks containing the
blkfs!

and remove cfspack, which will not ever be used again.

To update LATEST offset more easily. Will be useful for recipes.

Use it in shell instead of using popen()

ref #80

In C this time. Python/Perl code is barely terser than C for these little
tools. Why bother with interpreted?