Simple links to unknown names now get highlighted

Basically aping the usual Wiki behaviour of [[Unknown Page]].
Crucial fix to authentication pathways

Turns out that setProperty2() wasn't working, because unlike
setProperty(), it had requireLogin == true, and that wasn't respecting
Space-specific logins.

So did a non-trivial overhaul of the pathways, so that Space-based pages
let the Space decide whether this person has an authentication.

ALSO: fixed the Collections drop-down to no longer include internal
Collections that end users should never use.
Release 0.3.13.1