Internal: not, not NOT.
Internal: Standardize interface to canViewTags, etc.
Show paper manager.
Internal: Search: Pass around query info in an object.
Correct [?] 'NOT' compilation.
Search: Tag search obeys paper-manager rules.

This is the right way to check permissions -- don't try to do it in
SQL, do it in PHP. Unfortunately this is annoying.

Also fix a buglet (unreferenced property).