Re: Commit notes workflow

I'm still unsure what that limitation brings to us.  OTOH, it has at least one
funny downside: when someone tries to refer to some forbidden ref using --ref, it
gets silently requalified:

$ git notes --ref=refs/remote-notes/foo add
$ find .git/refs/notes/ -type f
.git/refs/notes/refs/remote-notes/foo
$

It just seems so wrong...  Surely we can mitigate it by considering a ref starting
with "refs/" to be absolute, and thus never prepend "refs/notes/" to it, but it rather
sounds to me a symptom that we may not want to filter things anyway.

While playing with this, I realized that when editing the template
does not name the notes ref being edited.  When looking at the code,
I notice that, contrarily to commit.c which uses stdio, notes.c uses
write_or_die(), which is a bit less flexible for formatting.

I'd think we could me things more consistent - is there any objection
to switch notes.c to using stdio for this ?