Commit 9081014 fixed most of the confusing issues between scope id and
scope however 844896d added bad limits checking assuming that the scope
is being set and not the scope id.
I have fixed the documentation so it all refers to scope ids.
In addition Curl_if2ip refered to the scope id as remote_scope_id which
is incorrect, so I renamed it to local_scope_id.
Adjusted-by: Daniel Stenberg
Closes#3655Closes#3765Fixes#3713
