[PATCH 3 of 4] acl: user docs for the "!" prefix in user or group names

[Dennis Brakhane]

On Tue, Jun 5, 2012 at 4:13 PM,  <elifarley at gmail.com> wrote:
> +1) Deny access to branch "ring" to anyone but user "gollum"
> +  ring = !gollum

I find this really confusing and error-prone, especially if a
programmers configures the acl. C and friends have taught us that
exclamation mark is read as not, so many people will probably read
that as "not gollum" and assume that everyone except gollum have
access, while it is in fact the opposite. And once someone who is not
gollum complains and you notice the error, gollum might already have
done the damage.

I strongy suggest some other syntax, even "gollum!" would be clearer
to me, I could read that as "gollum! and no one else!!!!oneone"