lfs: rename {oid} to {lfsoid}
Per Yuya, for consistency with {lfspointer}. It might be slightly confusing for
there to be {lfsoid} and {lfspointer.oid}. But preventing ambiguity seems more
important, and the latter is controlled by the git-lfs spec.
Set up
$ hg init repo
$ cd repo
Try to import an empty patch
$ hg import --no-commit - <<EOF
> EOF
applying patch from stdin
abort: stdin: no diffs found
[255]
No dirstate backups are left behind
$ ls .hg/dirstate* | sort
.hg/dirstate