[Toybox] Release 0.8.10

[Rob Landley]

I was _trying_ not to call in that (sorts terribly in the directory listing) but
I have goals for 0.9.0 I didn't achieve yet (test suite running under mkroot,
and maybe a basic LFS build too albeit starting out with a pile of supplementary
binaries). And after stretching the dev cycle out to TWICE normal release
length... I just did an 0.8.10 release.

In addition to the zillions of bugfixes and new command --flags, "dd" finally
got cleaned up and promoted, and a BUNCH of upgrades to mkroot. Shell's still in
flux and I need to get back to that this week. (The release happened by NOT
finishing and merging a bunch of pending work. Didn't check in the /etc/passwd
plumbing rewrite, didn't check in the fixes to make cp -s more robust like
readlink/realpath...)

I also hope to get https://landley.net/talks/mkroot-2023.txt actually recorded
soonish.

Rob