Clearer naming of nat override options

[willscott]

fix #874

[Stebalien]

@daviddias better?

[daviddias]

Not 100% sure, will sleep on it. I think the thing that makes it look foreign is that even for a Networks person, "reachability" as a property is not directly associated with NAT'ed vs. Public IPs. So it is a stepping stone to learn about, not huge though and the docs do help :)

[Stebalien]

I think the thing that makes it look foreign is that even for a Networks person, "reachability" as a property is not directly associated with NAT'ed vs. Public IPs.

That's actually what this option is trying to capture. The "AutoNAT" service is really trying to determine "am I directly reachable from the public internet", not "am I behind a NAT".